MD Julie Castagna
email: julie.castagna@aphp.fr

MD Emmanuelle Amsler

MD Flore Kurihara

MD François Chasset

MD, PhD Annick Barbaud

MD, PhD Angèle Soria

Atypical features of cutaneous adverse drug reactions during therapy

Hairy cell leukemia (HCL) is a rare mature B-cell leukemia. Patients classically display splenomegaly, pancytopenia, and typical hairy lymphocytes accumulated in the spleen and bone marrow. The purine analog cladribine is the first-line treatment for HCL and induces high rates of long-lasting remission. Recently, some publications have reported a high incidence of cutaneous adverse drug reactions (CADRs) in individuals with HCL treated with cladribine. [START_REF] Ganzel | High incidence of skin rash in patients with hairy cell leukemia treated with cladribine[END_REF][START_REF] Meher-Homji | High prevalence of antibiotic allergies in cladribine-treated patients with hairy cell leukemia-lessons for immunopathogenesis and prescribing[END_REF] Herein, we report clinical features and drug test results related to CADRs in patients with HCL after cladribine therapy.

All patients with suspected CADRs after cladribine therapy for HCL between 2005 and September 2019 in our department were included.

We retrospectively collected clinical data and drug allergy workup data. After chronological analysis of all suspected drugs, patch tests were performed first. If results were negative, skin prick tests and intradermal skin tests (for drugs with injectable form) with delayed reading at day 2 were performed for all suspected drugs (see Table E1 in this article's Online Repository at www.jaci-inpractice.org). Finally, challenge tests were administered for drugs that tested negative. For some patients and when necessary, cross-reactivity between drugs of the same class was explored.

Twelve patients were included (Table I): 5 women and 7 men with a median age of 52 years (31-68). Eight patients had maculopapular exanthema (MPE) with systemic symptoms (MPE-SS, systemic symptoms including fever and visceral involvement appearing simultaneously or in the few days following skin rash and with a RegiSCAR score < 4) (Figure 1, A), 2 patients had acute generalized exanthematous pustulosis (AGEP), and 2 patients had drug rash with eosinophilia and systemic symptoms (DRESS) syndrome (RegiSCAR score ≥ 4). For all patients, skin rash occurred during the aplasia stage, with a median occurrence at 12 days (10-15) after cladribine initiation. class was observed in 4 of 5 patients (Fig CADRs are skin manifestations resulting from systemic drug administration, ranging from erythema to much more severe reactions such as AGEP, DRESS syndrome, or toxic epidermal necrolysis with systemic involvement (hepatitis, interstitial nephritis, or pulmonary, cardiac, or pancreatic involvement). Moreover, overlapping features between MPE and DRESS syndrome, called MPE-SS, have been described, suggesting a continuous spectrum between both diseases, with minor forms of DRESS syndrome, also called MP/DR 3 and mini-DRESS, [START_REF] George | Systemic hypersensitivity reaction to Omnipaque radiocontrast medium: a case of mini-DRESS[END_REF] existing.

Thirty-eight cases of CADRs have been previously reported in patients with HCL treated with cladribine. Among them, 13 patients had systemic symptoms and 2 patients had severe CADRs (1 patient had DRESS syndrome, and 1 patient had lethal toxic epidermal necrolysis). The median delay in onset after cladribine introduction was 14 days (3-187). In 3 patients, a possible cosensitization to multiple drugs was suspected [START_REF] Ganzel | High incidence of skin rash in patients with hairy cell leukemia treated with cladribine[END_REF][START_REF] Grey | Severe skin rash in two consecutive patients treated with 2-chlorodeoxyadenosine for hairy cell leukaemia at a single institution[END_REF][START_REF] Kokunai | Hypersensitivity reactions to multiple drugs during the course of hairy cell leukemia treated with 2-chlorodeoxyadenosine[END_REF] but was confirmed in only 1 patient. [START_REF] Kokunai | Hypersensitivity reactions to multiple drugs during the course of hairy cell leukemia treated with 2-chlorodeoxyadenosine[END_REF] Meher-Homji et al 2 recently showed a higher prevalence of antibiotic allergy in cladribine-treated patients with HCL (26 of 43 patients [60.47%]), compared with that in cladribine-treated patients with hematological malignancies (14%) and that in fludarabine-treated patients with chronic lymphocytic leukemia or follicular lymphoma (25%). Among the 26 patients allergic to antibiotics, 3 had DRESS syndrome (RegiSCAR score = 4) and 1 had MPE-SS. Only 5 of 26 patients had allergological investigations with skin tests, results for which were positive for antibiotics in 4 patients, but cosensitization was not assessed. As in our series, cladribine was also not tested. Indeed, because of its lack of chronological imputability, having a very short elimination half-time, it is not considered as a causal agent.

We report for the first time a very high risk of cosensitization to CADRs in individuals with HCL treated with cladribine. Cosensitization is an unusual situation reported only in approximately 18% of patients with DRESS syndrome, whereas it occurs in relation to only 0.3% of other CADRs. [START_REF] Barbaud | A multicentre study to determine the value and safety of drug patch tests for the three main classes of severe cutaneous adverse drug reactions: drug patch tests for SCAR[END_REF] However, in cladribine-treated patients with HCL, cosensitization was frequently observed (41.7%), even in patients without DRESS syndrome criteria. We also found a risk of CADR reoccurrence after cladribine therapy.

HCL is a rare disease representing 2% of all leukemia and with an annual incidence of 1/500,000. Cladribine is always recommended; it is the first-line treatment. [START_REF] Ganzel | High incidence of skin rash in patients with hairy cell leukemia treated with cladribine[END_REF] CADRs seem to be more prevalent in HCL than in other hematological diseases treated with cladribine. [START_REF] Meher-Homji | High prevalence of antibiotic allergies in cladribine-treated patients with hairy cell leukemia-lessons for immunopathogenesis and prescribing[END_REF][START_REF] Barete | Long-term efficacy and safety of cladribine (2-CdA) in adult patients with mastocytosis[END_REF] Interestingly, in a cohort of 68 patients treated with cladribine for mastocytosis reported by Barete et al, [START_REF] Barete | Long-term efficacy and safety of cladribine (2-CdA) in adult patients with mastocytosis[END_REF] no patient declared CARD. Thus, the role of cladribine is not clear, but we hypothesize that durable immune alterations due to both cladribine therapy and the abnormal functionality of lymphocytes during HCL could be responsible for this high rate of CADRs. Indeed, a profound CD4 + lymphopenia, including regulatory T cells, is induced by cladribine and could result in hypersensitivity and decrease drug tolerance in patients with HCL. [START_REF] Ganzel | High incidence of skin rash in patients with hairy cell leukemia treated with cladribine[END_REF] This could be similar to the immune alterations induced by immune checkpoint blockade in melanoma, which enhance the risk of CADRs with other subsequent therapies. [START_REF] Naqash | Cutaneous adverse reactions in B-RAF positive metastatic melanoma following sequential treatment with B-RAF/MEK inhibitors and immune checkpoint blockade or vice versa: a single-institutional case-series[END_REF] However, there is no study confirming this hypothesis.

Allergists, dermatologists, and hematologists should be aware of the risk of potentially severe CADRs and the high risk of cosensitization for patients with HCL treated with cladribine.

  ; IDT, intradermal test; M, male; ND, not done; PT, patch test.Drug allergy evaluations were positive in 11 of 12 patients, and the results are presented in TableI. Antibiotics (cotrimoxazole, piperacillin-tazobactam, amoxicillin-clavulanic acid), valaciclovir, atovaquone, and iodinated contrast media were inducers in 7, 4, 4, and 2 patients, respectively. Cladribine was not implicated because of the lack of chronological imputability due to its short half-life of a few hours (5.4 hours). A cosensitization (defined by more than 1 positive drug skin test result and/or drug challenge test result) to different molecule classes was found in 5 of 12 patients. A cross-reactivity between molecules of the same

Figure 1 (

 1 Figure 1 (A) MPE in patient 4. (B) Drug skin test results for patient 12: positive patch test results for amoxicillin-clavulanic acid and 2 iodinated contrast agents (iodixanol and iobitridol) on day 2. (C) Reactivation of MPE on day 2 in patient 12 during positive patch test results for amoxicillin-clavulanic acid and iodixanol and iobitridol.

Table I

 I Clinical and allergological data in 12 cladribine-treated patients with HCL with CADRs

		M/31	histology MPE-SS/compatible with CADRs	treatment in days before reaction) Piperacillin-tazobactam (30), meropenem	positive skin test result/positive result provocation test
	1	F/43	MPE-SS/compatible with CADRs	Cotrimoxazole (10) (10), allopurinol	0/ND	No/ND	0
	2	F/59	DRESS syndrome/compatible with neutrophilic dermatitis	Valaciclovir (17), atovaquone (17), allopurinol (10)	Atovaquone (PT)/0	Yes/ND	MPE with amoxicillin 8 mo later
	3	M/54	AGEP/compatible with AGEP	Valaciclovir (21), cotrimoxazole (21)	Valaciclovir, (PT)/ND cotrimoxazole	Yes/yes (aciclovir)	AGEP with amoxicillin and IFN-α-2b 4 y later, DRESS syndrome with cefuroxime 8 y later
	4	F/36	MPE-SS/compatible with CADRs	Piperacillin-tazobactam (9), valaciclovir (9), atovaquone (9), clarithromycin (1), amikacin (1)	Piperacillin-(PT)/0 atovaquone valaciclovir, tazobactam,	Yes/yes (amoxicillin)	0
	5	M/55	MPE-SS/normal	Cotrimoxazole (10), amoxicillin-clavulanic acid (4) (4), ciprofloxacin	Amoxicillin-(PT)/0 clavulanic acid	No/ND	0
	6	M/50	MPE-SS/compatible with CADRs	Cotrimoxazole (10) (10), fluconazole	0/cotrimoxazole	No/ND	0
	7	F/64	DRESS syndrome/compatible with CADRs	Valaciclovir (10), atovaquone (10), cefixime (2) ciprofloxacin (2),	Atovaquone (PT)/0	No/ND	0
	8	M/43	MPE-SS/compatible with CADRs	Metoclopramide (10), cotrimoxazole (9), (3) (3), ciprofloxacin clavulanic acid amoxicillin-lederfoline (9),	Amoxicillin-(IDT)/ND clavulanic acid	No/ND	0
	9	M/47	AGEP/ND	Atovaquone (10), valaciclovir (10), ceftriaxone (1), iopromide (0)	Atovaquone, (PT)/ND iopromide valaciclovir,	Yes/no	0
	10	M/54	MPE-SS/ND	Cotrimoxazole (9), amoxicillin-clavulanic acid (4), ciprofloxacin (4), piperacillin-amikacin (0) tazobactam (0),	Amoxicillin-(PT)/0 tazobactam piperacillin-clavulanic acid,	No/yes	MPE with amoxicillin 5 y later
	No. 11 12	Sex/age (y) F/68 M/31	Clinical presentation/skin MPE-SS/compatible with CADRs MPE-SS/compatible	Suspected drug (duration of Cotrimoxazole (5), valaciclovir (5) Piperacillin-	Culprit drug confirmed with 0/valaciclovir Piperacillin-	Cosensitization/cross-No/ND reactivity Yes/yes (amoxicillin-	0 MPE with iomeprol 6 mo later	Recurrence

  1, B). Moreover, 4 patients had at least 1 other CADR (3 MPE, 1 DRESS, and 1 AGEP) several months/years after the first episode; the additional CADR appeared after readministration in patients 10 and 12 and after new sensitization to another drug class in patients 2 and 3, confirmed by drug allergy evaluations (see TableE2in this article's Online Repository at www.jaciinpractice.org). For patient 12, reactivation of MPE, without systemic symptoms, was induced by drug skin tests (Fig1, C). All patients were in the aplasia stage during CADRs, and 8 of 12 patients still had lymphopenia at least 6 months after cladribine administration, including 3 of 4 patients with CADR reoccurrence.

Acknowledgments

We thank Dr Hafida Gaouar, Dr Tullia De Risi-Pugliese, and Dr Aurore Hamelin for providing cases and for their help in the realization of this work. We obtained written permission to include their names in the Acknowledgments section.

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Ballatore Marta

Lise Arena

Amel Attour

When an Institutional IT Renews a Connected Vehicle Ecosystem: Evidence from the trust-mediator Role of Blockchain Technology *

Keywords: Blockchain, trust, institutional technology, connected vehicle, ecosystem renewal

This research focuses on the role of blockchain technology as a vector of inter-organizational trust in a reconfiguring ecosystem phase. Using qualitative analysis of data mainly from semistructured interviews, this study focuses primarily on the deployment of this emerging technology within a connected automotive ecosystem. Based on the notion of "trust-mediator technology", we show how blockchain technology is perceived as an institutional technology offering a new form of governance for all transactions and exchanges between the ecosystem actors. Although the functionalities offer automation to reduce the use of trusted third parties, preliminary results still show a strong commitment to current governance systems, such as regulatory and contractual frameworks. Ecosystem actors consider that complementarity between traditional institutional structures and decentralised blockchain is paramount for the success of any cooperation and collaboration on data on a connected vehicle.

Quand une technologie institutionnelle renouvelle un écosystème de véhicules connectés : Enjeux empiriques de la technologie Blockchain comme médiateur de confiance * Ballatore Marta, Lise Arena, Amel Attour Université Côte d'Azur, CNRS, GREDEG

Résumé en français :

Cette recherche se concentre sur le rôle de la technologie blockchain en tant que vecteur de confiance inter organisationnelle dans un écosystème en reconfiguration. En utilisant une analyse qualitative de données provenant principalement d'entretiens semi-directifs, cette étude se concentre sur le déploiement de cette technologie émergente au sein d'un écosystème véhicules connectés. En s'appuyant sur la notion de "technologie médiatrice de confiance", nous montrons comment la technologie blockchain est perçue comme une technologie institutionnelle offrant une nouvelle forme de gouvernance pour l'ensemble des transactions et des échanges entre les acteurs de l'écosystème. Bien que les fonctionnalités offrent une automatisation permettant de réduire le recours à des tiers de confiance, les résultats préliminaires montrent encore un fort attachement aux systèmes de gouvernance actuels, tels que les cadres réglementaires et contractuels. Les acteurs de l'écosystème considèrent qu'une complémentarité entre les structures institutionnelles traditionnelles et la décentralisation de la blockchain est primordiale pour le succès de toute coopération et collaboration en matière de données sur un véhicule connecté.

Mots clés : Blockchain, confiance, technologie institutionnelle, véhicule connecté, reconfiguration d'un écosystème

Introduction

In the current digital transformation context, new generations of digital technologies revolutionise industries and society. In a recent definition of its business impacts, [START_REF] Vial | Understanding digital transformation: A review and a research agenda[END_REF] describes "digital transformation" as a process initiated by technology disruption, leading to a strategic response from organisations and giving rise to value creation at all levels, including ecosystem ones. In this new context of emerging technologies, blockchain technology (henceforth, BCT) aims at providing a trusting data-sharing solution for both organisations and end-users. So far, IS scholars mainly focus on the technological implementation of blockchain at the organisational or governmental level [START_REF] Kokina | Blockchain: Emergent industry adoption and implications for accounting[END_REF][START_REF] Batubara | Challenges of blockchain technology adoption for e-government: a systematic literature review[END_REF][START_REF] Duy | A survey on opportunities and challenges of Blockchain technology adoption for revolutionary innovation[END_REF][START_REF] Holotiuk | Organisational adoption of digital innovation: the case of blockchain technology[END_REF][START_REF] Clohessy | Investigating the influence of organisational factors on blockchain adoption: An innovation theory perspective[END_REF]. Existing research also emphasises the role of external/environmental variables in the adoption process of organisations [START_REF] Schmitt | Smart contracts and Internet of things: A qualitative content analysis using the technology-organisationenvironment framework to identify key-determinants[END_REF][START_REF] Chang | Is a Disruptive Technology Disruptive? The Readiness Perspective Based on TOE[END_REF][START_REF] Malik | An Exploratory Study of the Adoption of Blockchain Technology Among Australian Organisations: A Theoretical Model[END_REF], and the importance of BCT in improving interorganisational dynamics (e.g., at the supply chain level, Wong et al. 2019). More recently, scholars claim that one of the main benefits associated with Blockchain technology is its trustmediator role (Bodò 2020) and its potential in shaping collaboration and cooperation [START_REF] Lumineau | Blockchain governance-A new way of organizing collaborations?[END_REF]). Yet, existing contributions lack understanding of this trust-mediator role in inter-organisational dynamics and changes at the ecosystem level. This gap in the literature is problematic since, in reality, traditional organizations are leveraging BCT according to its benefits in shaping new and current collaboration and cooperation. New consortiums are emerging at the industry and ecosystem level, specifically following blockchain's definition as a "trust machine"1 . BCT's trust-mediator role is particularly relevant to study when looking at the renewal phase of a specific ecosystem. It is assumed that traditional business models' digital transformation occurs at the renewal phase of their ecosystems. Defined as the fourth phase of an ecosystem life cycle [START_REF] Moore | The Death of Competition: Leadership and Strategy in the Age of Business Ecosystems[END_REF], renewal occurs when innovations imperil mature business communities -as it is the case with BCT implementation in the connected vehicle ecosystem stressed in this paper. During this fourth phase, the main challenge for ecosystem members is to ensure their competitive survival. This requires reconfiguring the ecosystem's core elements and related complementary components. While strategic challenges (coopetition and leadership management) faced during this activity have been stressed in the seminal work of Moore (who used the traditional auto-industry as empirical context; 1996); less is known about the role of disruptive technology, such as BCT, in achieving reconfiguration of an ecosystem, as a whole. As a result, this paper leverages the concepts of trust by technology and mediated trust (Bodò 2020[START_REF] Söllner | Understanding the formation of trust in IT artifacts[END_REF]) to analyse how BCT (and its applications, such as smart contracts 2 ) establishes new logics of trust creation or transformation of pre-existed trusting relationships between ecosystem members. This paper provides an understanding of the role of BCT for shaping trust dynamics in the renewal phase of a connected vehicle ecosystem. It contributes to the existing literature on BCT by questioning the main benefits of this technology in trust dynamics through the analysis of two use cases. Our research contributes to the literature by challenging an emerging perspective considering BCT as an "institutional technology". We mainly question the coexistence of social and regulatory-based procedures with the new technology-based mode of organization. Consistently, the aim of the paper is threefold. First, it provides evidence on BCT's role as a trust mediator in an ecosystem reconfiguration. Second, it offers an original contribution to the IS literature dealing with "institutional technology" (Davidson et al. 2018) looking at the shift from a traditional governance system to new coordination mechanisms offered by BCT. Last but not least, at a more empirical level, this paper illustrates the use of BCT in the automotive industry, which is significantly less studied than other sectors (such as finance and industry).

In line with its main content, this paper falls into five main parts: 1) A literature survey on blockchains as 'institutional technologies'; 2) the empirical context of the paper -the role of BCT in a connected vehicle ecosystem; 3) the research method; 4) preliminary results and 5) concluding remarks.

Blockchains as "institutional technologies" enabling digital transformation

The invention of blockchain in 2008 is emblematic of the current digital transformation era, seen as a complex phenomenon triggered by significant changes brought about by digital technologies in the automation of business processes and company's business model and ecosystem. Scholars still diverge on the distinctive nature of digital transformation strategy; some arguing that digital strategy should be implemented as a part of a firm's IT strategy; while others claim that digital transformation demands a standalone strategy that is not part of a functional strategy [START_REF] Hess | Options for formulating a digital transformation strategy[END_REF]. [START_REF] Vial | Understanding digital transformation: A review and a research agenda[END_REF] argue that the current digital transformation process generates changes in value creation paths. It is increasingly fostered by relationships between people, groups of people and organisations, on the one side, and between users and innovative digital technologies, on the other. Hence, a digital strategy cannot be exclusively aligned with the firm's IT strategy anymore but has to develop at the ecosystem level. This is especially the case when one studies the distinctive features of blockchain and its recent economic implications.

Blockchain technology as an enabler of new forms of economic activities' coordination

Recent contributions reject the definition of blockchain as a "traditional" digital platform defined as firm operating multi-sided markets. By contrast, blockchains are seen as a new category of digital platforms where "management is distributed, or decentralised across a large number of (...) block validators and developers" [START_REF] Allen | Blockchain and the evolution of institutional technologies: Implications for innovation policy[END_REF]de Filippi & Lovelock, 2016). Initially introduced in the field of institutional economics, the concept of "institutional technology" is concerned with processes and mechanisms that enable alternative systems of governance for economic exchange and economic activities' coordination (Davidson et al. 2018). Since "institutional technologies" operate at the economic organisation level, they differ from traditional "industrial technologies" that usually impact industrial productivity inside the firm. To that extent, while introducing new forms of coordination and governance, blockchains facilitate "institutional entrepreneurship" and shift adoption issues from individual to group level. To sum up, blockchain technologies enable a wide range of governance systems, including those based on commons management [START_REF] Ostrom | Governing the Commons: The Evolution of Institutions for Collective Action[END_REF].

Consensus protocols, smart contracts, and other blockchain features provide new forms of coordination, especially throughout the appearance of new digital platforms for facilitating data transferring and transactions between organisations. Therefore, blockchain technology is defined as an assemblage of processes and mechanisms that enable new governance systems for coordination (Alen et al. 2020). Because blockchains can drive new forms of coordination between economic activities, it is worth wondering what drives actors to participate in a blockchain-based ecosystem. BCT's mediator role between heterogeneous actors is the working hypothesis formulated in this paper.

Trust as a blockchain technology benefit enabling the digital transformation of an ecosystem

A community of heterogeneous actors producing value-based goods and services to customers, who are themselves members of this community is defined as a business ecosystem [START_REF] Moore | The Death of Competition: Leadership and Strategy in the Age of Business Ecosystems[END_REF]. As a business ecosystem matures, it faces four fundamental challenges that respectively characterise the four phases of its life cycle: birth, expansion, authority and renewal or death (ibid). To avoid death, the ecosystem's keystone actor must succeed in achieving one main challenge: "ensuring that the business sustains continuous performance improvement" (ibid, p. 83). Several strategies or processes, such as digital transformation, could be chosen to realise such improvement. The use of new digital technologies to improve major business or uncover new ways to create value is defined as a digital transformation process [START_REF] Vial | Understanding digital transformation: A review and a research agenda[END_REF]. As a result, implementing blockchain technology in the extant product architecture of an ecosystem should improve one or more value creation mechanisms. This potentiality can be identified through BCT's benefits. As its main advantage is to be presented as a "trustless consensus engine", BCT's material properties reflect such benefits [START_REF] Beck | Blockchain-the gateway to trust-free cryptographic transactions[END_REF], Werbach 2018a). Here, it is argued that two main types of trust have to be considered to analyse how an ecosystem can improve its business performance by shifting to new system governance of its economic activities' thanks to blockchain technology: 1. Interpersonal trust mediated by technology (Bodò, 2020). One prerequisite condition to reach this level of truth is to develop an initial "trust in technology" (Sollner, 2011 andMcKnight et al. 2011). In this paper, because we look at extant coordination of economic activities in which actors are familiar with blockchain technology, it is assumed that this prerequisite condition is implicitly validated. As claimed by Bodò (2020, p. 2), blockchains shape "how humans trust each other, and that in order to fulfil this task, they need to be trustworthy". Put differently, we will assume free trust in the blockchain protocol. 2. Institutional trust (Davidson, 2018). Because of the technology's governance-related nature, the second category of trust is concerned with third-party verification. Secured blockchains are seen as a 'trustless' distributed ledger. The production of consensus avoids requiring centralised trust. As pointed out by [START_REF] Allen | Blockchain and the evolution of institutional technologies: Implications for innovation policy[END_REF], blockchains' diffusion as institutional technologies questions institutional stability. The new room given to institutional entrepreneurship underlies an increasing competition between 'blockchain-based institutions' and 'existing' traditional institutions. This coexistence is also questioned in this paper:

How do new forms of blockchain-supported governance and more traditional governance mechanisms could coexist in the same ecosystem?

To answer this question, we choose to conduct a qualitative case study on the connected vehicle ecosystem's digital transformation.

Blockchain implementation in the connected vehicle ecosystem: The case of Renault

The Smart Mobility transition refers to the digital transformation in the mobility system [START_REF] Docherty | The governance of smart mobility[END_REF]. Smart Mobility is an outstanding example of digital transformation involving emerging technologies, such as the Internet of Things, peer to peer applications, connected vehicles and autonomous systems challenging industry and, more broadly, all players in the ecosystem. Indeed, the idea of having a single automotive manufacturer taking care of all activities from design to final vehicle assembly is outdated given today's globalisation. Today, a global network of small and large players deals with vehicle components' production and assembling, and their activities' coordination (e.g., design, logistics, production) could be sometimes challenging. For this reason, several automotive players are investigating the potential of blockchain technology to simplify, secure, and perform coordination mechanisms at the industrial level (see, blockchain projects of Mercedes-Benz, Ford for supply chain). BCT will provide a transparent and trustable environment for collecting, validating, storing and sharing data, also throughout the use of smart contracts. As a result, new collaborations will conceive a customer-based approach in offering smart mobility services. Moreover, the end-users will also directly benefit from the blockchainsystem during the vehicle's whole ownership duration. Such digital transformation leads to a renewal of the core connected vehicle ecosystem with the entrance of new actors and/or the digitalisation of extant members' interactions (Figure 1). This renewal results from Original Equipment Manufacturers (OEMs), insurance companies, and banks, efforts to conceive and deploy innovative services that meet new needs related to emerging technology use, such as BT.

Figure 1: An illustration of a Connected Vehicle Ecosystem

To study the trust-mediator role of BCT in ongoing ecosystem reconfiguration, we investigate the connected vehicle ecosystem of Renault Group. The French automotive manufacturer collaborates with other automotive industry players, financial and insurance companies in blockchain projects. Those projects are conducted at several phases of a vehicle's life cycle. For our study, we selected two projects that together cover all stages of a vehicle's life cycle: eXtended Compliance End to End Distributed (Xceed) project and Smart IoT Mobility (SIM) project. Figure 2 shows how the two projects provide a comprehensive overview of blockchainbased certification and data sharing around connected vehicles. The following subsections details both projects by illustrating the series of events covered by each of them. Besides, we outline the main differences between the two projects (e.g., the nature of the collaboration, the project actors, the project phase).

Automotive Industry: a matter of certification of compliance information from design to production (Xceed Project)

Xceed project is an inter-organisational collaborative project around connected vehicles involving Renault Group and its major automotive industry partners like Continental, Faurecia, Plastic Omnium, Saint-Gobain. The project aims to adopt a distributed ledger as a unique "source of truth" from vehicle design to production -XCEED project launched in 2019. A blockchain-based record-keeping would provide reliable information on each subcomponent that boosts regulatory conformity in the automotive industry. Moreover, trust among stakeholders seems to be another driver for blockchain adoption. The distributed ledger is seen as the basis for a trusted network for sharing data and information.

Our study considers the Xceed project to analyse blockchain's role in transforming existing relationships between industry actors and exploring this technology's role in creating new collaborations with new entrants in the industry. This study has relevance since, in September 2020, Renault Groupe officially releases press news about successful tests on the blockchain system deployed in collaboration with IBM: "Testing at Renault's Douai plant was used to consolidate the value and performance that blockchain technology delivers for the automotive industry, with over one million documents archived and a speed of 500 transactions per second". Therefore, blockchain's industry-wide adoption is no longer seen as a potential long-term event.

To summarise, the XCEED project reflects an industry-wide collaboration about entering the "execution" phase.

Smart Mobility Services: a matter of digitalisation for data sharing about vehicles' life cycle (Smart IoT for Mobility project)

SIM project is an interdisciplinary research project involving industrial and academic actors (combining different academic fields: management, economics, computer science, microelectronics and law). It started in 2017 and granted ANR funding in 2019. A multidisciplinary team composed of academics and industrial partners (Renault Software Lab and Symag) aims to develop a transdisciplinary approach to investigate the digitalised transaction between actors through smart contracts and develop a distributed infrastructure for connected vehicles' data sharing. Academic experts in law are exploring the legal context of smart contracts. Micro-electronics scholars are simulating these contracts at the scale of IoT sensors. Computer Scientists are establishing a more comprehensive computer language. Finally, economists and management researchers are studying the adoption and acceptability of blockchain at end-users level; for that purpose, they need to understand the final supply's organisational architecture. All academics and industrial partners work together on several case studies, so-called events of a connected vehicle's lifecycle. Table 1 provides a set of examples of events to show blockchain benefits such as information asymmetry reduction, increased process objectivity, reduced need for trust in service providers and counterparties, identified by the project partners.

Event Description

Technical control

Ecosystem players (e.g. car repair shops, vehicle owners) see all information about the vehicle before and after the technical reparation.

Accident

At the moment of a collision, all information about the driving behaviour and vehicle status is uploaded automatically. Information asymmetry between insurers and insurance companies and expert intervention in determining accident dynamics are reduced.

Second-hand Sale

The information asymmetry between seller and buyer is reduced by the availability of reliable information on the blockchain.

Table 1: Examples of vehicle life cycle events and blockchain benefits

This project provides a suitable environment to study BT's role in ensuring a trustworthy environment at the ecosystem level. We explore blockchain in an ongoing collaboration that aims to define its role across business and technical requirements.

Research methodology

Case studies are commonly recognised as appropriate when the research question asks the "how" or "why" of a current set of events over which the researcher has little control [START_REF] Yin | Case study research: design and methods[END_REF]. This research seeks to understand "how" BCT and its applications, such as smart contracts establish new logics of trust creation or transformation of pre-existed trusting relationships between ecosystem players. Hence, based on a multi-case theory-building approach, the following section first introduces our data collection based on participant and non-participant observations. Second, it describes the qualitative research design.

Data collection and interview process

The analysis of BCT's institutional role in reconfiguring the dynamics of smart mobility ecosystems (i.e. trust in technology and trust by technology) is based on a series of 6 semidirective exploratory interviews, for a total of 7 hours and 55 minutes long of recording and 150 pages of transcript. We interviewed (and are still interviewing) blockchain experts from key organisations dealing with connected vehicles' data exploitation and valorisation. To ensure an illustrative sample, we interviewed employees at all carrier levels from R&D and Innovation departments of a French Original Equipment Manufacturers (OEMs), and a French Credit Group operating in Financial and Insurance Services. First, we started with a within-organisation (Renault, Symag) analysis to study organisational variables and the blockchain perspective. Second, we began with a within-case (Xceed and SIM projects) to investigate each variable and provide a project-based overview of BCT's role. Each case was analysed separately using the interview transcripts and secondary data (e.g., minutes, press releases). In conclusion, we made a cross-comparison analysis to process results. At all the steps, we synthesised the content for each code. The goal was to find similarities between the two cases and project players' perception to draw conclusions on BCT's role in providing trustworthiness on business collaboration and transactions.

Preliminary results

This section highlights preliminary results by focusing on BCT's trust-mediator role. More precisely, we identify what drives economic actors to participate in a blockchain-based ecosystem. First, we show how BCT differs from "traditional" technology by identifying its functionalities and related benefits for interorganizational collaborations and cooperation, demonstrating how the notion of institutional technology fits blockchain technology (subsection 5.1). Second, we recognise how blockchain technology's institutional role is perceived as the ability to generate or overcome inter-firm trust (subsection 5.2). To conclude, we show how traditional institutional structures are complementor to BCT decentralization to foster ecosystem reconfiguration adhesion.

BT as an Institutional technology

Primarily based on its functionalities, the blockchain is perceived as a new form of governance among ecosystem players.

BCT features, such as decentralisation, transparency, immutability, and security foster collaboration at all the ecosystem levels (automotive industry or mobility services' ecosystem periphery). Therefore, the technology is not perceived as a "traditional" IT artefact but as an innovative option in transaction management (distributed, automated, and decentralised) for value exchanges between ecosystem players. This definition also includes the customer (e.g., driver, vehicle owners).

"This technology certifies all exchanges by relying on the computer contribution of network members." Symag press release 2018 "For Groupe Renault, it has to be used as a collaborative, multi-company digital tool within the automotive sector." Renault press release 2020

Because blockchain technology drives new forms of coordination at the ecosystem level, each player's relationship is evolving in terms of partnership. Interviewees identify the protocol run with a peer-to-peer network of servers, smart contracts self-execution, and consensus protocol as factors guaranteeing the profits sharing, responsibilities, and risks between ecosystem players. Therefore, Blockchain experts pointed out that blockchain technology also provides a technological basis for "the automotive industry's competitiveness and operational excellence." Related benefits are also identified at the periphery level of the ecosystem in ensuring collaboration for smart mobility services (e.g., between insurance companies and OEMs).

To sum up, interviewed experts consider blockchain as a new environment for data sharing, principally allowing cost-cutting and new value creation. The distributed ledger is viewed as a generator of a unique procedure to share data between ecosystem actors. More precisely, experts pointed out that blockchain technology flatters the ecosystem network by providing objective data exchange governance. This positive perception is mainly based on each step of a transaction's potential automation, allowing accurate description and execution of agreements. Put differently, the distributed ledger helps economic actors to overcome information asymmetry characterising traditional deals between them. Moreover, experts underline that real-time data sharing provides the basis for an "ecosystem collective intelligence," providing reactivity in evaluating and adapting to future demands and needs.

Blockchain functionalities and benefits for inter-organisational collaboration and cooperation

IS research and other fields such as computer science and digital law have already highlighted the disruptive nature of blockchain by listing various functionalities and related benefits for organisations, customers, and, more in general, for data sharing and transactions (e.g., [START_REF] Beck | Blockchain-the gateway to trust-free cryptographic transactions[END_REF][START_REF] Mathews | BIM+Blockchain: A Solution to the Trust Problem in Collaboration? CITA BIM Gathering[END_REF]. Our primary analysis provides a list of blockchain and smart contract characteristics with positive spillovers on inter-organisational collaboration and cooperation. Table 5 shows the relationship between blockchain's specific features and related benefits for the ecosystem.

"at the center of the value, you find trust within the ecosystem (industry) Table 5 shows BCT's direct influence and smart contracts' specific characteristics on the connected vehicle ecosystem renewal. For instance, traceability of transactions and data access seems to play a crucial role. BCT ensures a detailed register for data storing, data treatment, and data sharing. Above all, traceability generates a reputation effect among economic actors.

For example, at the supply chain level "it influences the relations between suppliers, the fact that everything is traced and that everyone is aware of it on both sides" Research Engineer, Renault Software Lab 2020. Secondly, traceability also provides a solution for regulation conformity, such as GDPR. Moreover, we found that BCT's ability to ensure data and transaction governance by design is also perceived by ecosystem actors as a getaway from the present ecosystem configuration. Reactivity and efficiency are the two main benefits highlighted by interviewees. Both projects -Xceed and SIM -adopt the blockchain to renew communication and collaboration practices relying on technology design. "The objective is to manage communication in an automatic way for partners for whom the sharing and the compensation would be at a blocking point" Renault Software Lab, Research Engineer 2020.

To sum up, blockchain design enhances the ecosystem renewal by bringing new opportunities based on cost-cutting procedures and inter-organisational efficiencies. Therefore, the institutional role of BCT is mainly based on design propriety. Since the IS literature pointed out the importance of security, privacy, and data integrity issues for trust in IoT-based transactions, these constructs may be considered "indirect" factors affecting the trust between ecosystem actors. More research is necessary on this point.

Trust by BT: the mediator role of BCT in the ecosystem renewal phase

In the previous subsection (5.1), we show how the blockchain's design influences the interest of the ecosystem actors to renew the ecosystem dynamics. This subsection demonstrates how BCT is perceived "The blockchain aims to create a network of trust between OEMs and vehicle manufacturers to share compliance information" News release Renault Group, 10th September 2020 as a trust-mediator providing trust among ecosystem players. In this case, the technology design is the primary trust construct emphasised by interviewed experts.

The following trust constructs refer to blockchain characteristics already emphasised in the previous section and directly associated by interviewees with trust improvement at the ecosystem level.

Automation plays a crucial role in BCT's institutional perception in ensuring trust between economic actors. For instance, smart contracts' selfexecution is seen as a vector of reliability and security for data sharing. Put differently, this application of blockchain provides a technological process that ensures the immutability of information and transaction conditions. As a result, interviewees underline the potential replacement of traditional trusted third parties.

Data availability refers to the availability of a copy of the blockchain for each network's peer (node). BCT provides distributed access to information. This functionality not only improves trust and reactivity among ecosystem actors it also enables players to respond to the present uncertainty regulatory environment. Respondents mentioned that the regulatory system seems to evolve to force them to share data.

Data certification and security refer to information immutability once it is encrypted in the blockchain system. This ability of the ledger to stay unchangeable allows partners to reduce the need for third parties to generate trust between them.

Werback (2018a) highlights BCT's role in ensuring interpersonal trust. In this subsection, we extend the notion of trust mediation at the inter-organisational level. Our results demonstrate how BCT allows ecosystem actors to trust each-other by removing the uncertainty of parties' actions. This institutional technology incentivises the ecosystem renewal by fulfilling the role of trust-mediator technology.

Institutional-based trust: the role of structural assurance components in BCT conception, adoption, and intention to trust.

Our analysis also highlights the positive role of structural assurance components in interviewees' reflections. Structural assurance refers to beliefs that the success of a technology outcome is related to the presence of supportive conditions and equipment [START_REF] Mcknight | Initial trust formation in new organisational relationships[END_REF]. Rather than perceiving BCT as a unique institutional structure enabling ecosystem transactions and inter-organisational trust, results point out the complementarity of blockchain institutional features with traditional legal, physical, and contractual arrangements. Interviewees perceive that blockchain-based transactions are likely to be successful thanks to "If there is information that comes up that is considered reliable, there are a lot of cases where they (the partners) are not going to be obliged to involve experts (trusted third parties), they are going to be able to trust the feedback that is given so there are a number of smart contracts that will automate actions and operations" CIO 2020 "There are regulatory changes which mean that more and more, in order to promote competition between players, players are led to share data, (...) we want to have more and more confidence and the best way to have confidence is to tell ourselves that we have access to information" CIO, 2020 "But when you work with external companies, when you need to certify information in a trustworthy mode without a third-party certification (...) blockchain is now the really ideal solution" Presentation Lyon Blockchain Stampede, VP Blockchain, Renault, 2020 "Secure and certified network exchanges between partner companies or between members of an ecosystem". News Release, Renault Groupe, 14th May 2020 supporting situations and structures. These findings are in line with Werbach 2018b. Despite the hype around blockchain's disruptive nature, we found a persistent attachment to traditional structures and competencies. The role of lawyers and business departments is perceived as crucial in two critical phases: (i) the conception of the blockchain system or a smart contract, "there will always be lawyers, and commercial services that will agree on an outline, at least perhaps to activate or not to activate such and such an offer" CIO, 2020; (ii) and the handling of potential problems encountered at the end of the automated process, "(...) even with automated processes you can find cases where the automation will fail, so it won't prevent at some point maybe to go back to what happened in an automated way." CIO, 2020. On the same line, consortium agreements and traditional contracts are also considered necessary to construct the BT network and the collaboration determination.

"I imagine is that a lot of things are going to be written in the constitution of the consortium that is going to create the blockchain because the blockchain, in the beginning, is a consortium, so there is an agreement between the parties, (…), then it will be smarts contracts-based governed, no doubt by templates that will have been previously validated on both sides (...)" Research Engineer, 2020

Interviewees also highlight the interdependence of the blockchain-based ecosystem mediation's success with other technologies creating the basis for blockchain usage. Interviewees emphasised that 5G technology's appearance ensures real-time data sharing with connected vehicle sensors.

"The car needs to be able to access a network at all times to be able to send the data to be certified, and so with the emergence of 5G, we're going to be able to resolve some of these constraints, it's going to allow better connectivity, better responsiveness, and so we should be able to set up these use cases". Interviewee 1, 2020 Moreover, they underline the role played by IoT systems reliability. The latter shows the context-dependency of BT's success. BT ensures the reliability and immutability of information and transactions from when data are stored in the ledger. Therefore, IoT systems' trustworthiness is crucial for providing reliable data collection.

Discussion and Conclusion

In line with institutional approaches (Alen et al. 2020), this paper showed how BCT could determine a distributed governance for both networking and verification costs [START_REF] Catalini | Some Simple Economics of the Blockchain[END_REF]. Our results also share the definition of BCT as a "trust-free system" (see [START_REF] Beck | Blockchain-the gateway to trust-free cryptographic transactions[END_REF]. BCT is perceived as an institutional technology providing logics and rules for intermediation between ecosystem actors. We found that at the vehicle connected ecosystem level, the decentralised and automatic protocol is perceived as a "gateway" from interorganizational trust by guaranteeing the success of transactions. We assist to a shift from interorganizational trust to BCT as a trust-mediator (Bodò 2020). Transaction certainty is provided by technological functionalities. Yet, this study shows that interviewees perceived this BCT mediation as not sufficient to provide a trustworthy ecosystem environment. Structural assurance seems to be essential to ensure the intention of ecosystem players to participate in ecosystem renewal. We underline the complementarity of institutional technology to traditional institutional structures allowing to manage competition/cooperation tension during the renewal phase. "It's a tool that will facilitate the exchange of data in an operating mode with a governance system that opens up our new use cases, that will automate certain things that require a lot of manual processes, but that won't take away any know-how" CIO, 2020

Our results also underline a context-dependency of BCT which is mainly pointed out when interviewees list present constraints in implementing this distributed system at the ecosystem level. Three main types of requirements for implementation have emerged: (i) technological (performance, scalability, volatility, and robustness), (ii) organisational (organisational openness to strategic positioning changes, and top management reluctance), and "interorganizational" (BCT value determination). These factors majorly refer to the association of BCT to IoT systems (connected vehicles), and the intention to implement the BCT with peripheral ecosystem actors (insurance companies, banks, peer to peer applications). Therefore, these constraints have principally emerged during discussion about the SIM project. The low level of understanding and the perceived immaturity of BT are the major factors affecting the slowing ecosystem renewal based on decentralisation. Second, a fully BCT-based system requires a disruptive shift from traditional ecosystem practices to technology-based ones. Consistently, at the theoretical level, the paper contributes to the literature on BCT adoption. In particular, it shows a persistent attachment to traditional social-and regulatory-based procedures which is mainly due to technological, organisational and interorganizational inhibitors. The trust-mediating role of the BCT is enabled by the presence of traditional modes of organization that provide a bridge between current ecosystem dynamics and the disruptive potential of the BCT as an institutional technology. From a practical perspective, the article highlights a "hybrid mode" combining benefits of BCT and traditional organizing mechanisms. This "hybrid mode" of coordination provides a way for companies that are still facing technological, organizational, and interorganizational inhibitors. Our preliminary results also demonstrate that our interview themes and coding systems provide a fruitful basis for investigating the trust-mediator role of BCT in ecosystem dynamics. In addition, combining primary data with secondary data from public publications and presentations allows us to have a more complete analysis. Because of the limited sample of interviewees so far, this paper does not aim to develop a full theoretical contribution on the institutional role of BCT in mediating trust by providing an interorganizational trust-free system for transactions and data sharing. Yet, we consider contributing to the understanding of the socio-technical dynamics around BCT by providing an overview at the ecosystem level. For further research, we will supplement our data collection with other primary data with a more robust qualitative analysis. We also consider extending this analysis to business departments, interviewing non-technical work profiles. Another limitation refers to the decision of not focusing on the perception of trustworthiness of blockchain technology (trust in technology). However, this analysis shows technology functionalities that interviewed experts have emphasised in ensuring trust by technology. Future research is required to analyse the role of trust in technology in ongoing ecosystem renewal phase.

Figure 2 :

 2 Figure 2: Illustration of the case study: the data certification of all the events concerning a vehicle's life cycle.

  Table 2 provides an overview of the experts interviewed.

	Code	Description	Example
	Technology	Technological features affecting the	"Both have the certainty that the message was well-mitted and received with an
	Functionalities	ecosystem renewal	unmodified content." Lyon Blockchain Stampede, Blockchain Technology Expert,
			Renault, 2020
	Benefits for	BT-based benefits at the ecosystem	"The objective is to be able to communicate automatically with partners for whom,
	coordination	level	how to say, the sharing, the remuneration would be at a blocking point". Research
			Engineer, Renault Software Lab, 2020
	Institutional	governance-related nature of the	"(...) it's a tool that will facilitate the exchange of data in an operating mode with a
	Technology	technology	governance that opens up our new use cases, that will automate certain things that
			require a lot of manual processes" CIO Symag, 2020
	Trust by technology	Interorganizational trust mediated by	"It's a great tool for partners to trust each other" Research Engineer, Renault
		BT	Software Lab, 2020

Table 4 : Code scheme of our data analysis

 4

Decentralisation and encrypted modes to foster data control and confidentiality

  and outside of it you change from a customer supplier relationship to a partner relationship". Presentation Lyon Blockchain Stampete, VP Blockchain, Renault, 2020 "It's a tool that will facilitate the exchange of data in an operating mode with governance that opens up our new use cases". CIO Symag 2020

	"The decentralised nature of blockchain technology allows each party
	to maintain control and confidentiality of their data, without intrusion,
	while enhancing security and privacy" News release Renault Group,
	10th September 2020

The immutable nature of blockchain and the traceability provide data integrity to ensure authentication and avoid fraudulent/opportunistic practices Albrecht (2018). As a result, services and products quality improves

		"Both have the certainty that the message was well-mitted and received
		with an unmodified content." Lyon Blockchain Stampede, Blockchain
		Technology Expert, Renault, 2020
		"the quality of everything that was supplied was much improved because
		we know that it is traced, that it can be seen as unchangeable, etc. So
		clearly the technology is improving the quality. "Research Engineer,
		Renault Software Lab 2020.
	Data Availability (transparency) enhancing reactivity and efficiency at the ecosystem level	"It allows for better reactivity in exchanges, with data available in real-time and greater efficiency within a network that is no longer centralised but distributed." News release Renault Group, 10th September 2020
		"They (consortium blockchains) require access permission of our
	Access Permission to allow data exchange	participants, yet they allow companies with different interests to
	in a secure way	exchange securely." Lyon Blockchain Stampede, Blockchain
		Technology Expert, Renault, 2020
	Technological compatibility to facilitate
	the adoption by several players

"you get reactivity in implementation of blockchain as it

is not very intrusive in the information system of each company

.

" Lyon Blockchain Stampede, VP Blockchain, Renault, 2020

Table 5 : blockchain functionalities and related benefits at the ecosystem level

 5

Definition from The Economist, October 31,

2015, "The Trust Machine".2 In 1997, Nick Szabo defines smart contracts as computerised protocol that implement clauses and terms of a contracts in an automatic manner. These digitalized contracts are considered as one of the most promising uses of the blockchain.

* This work has been supported by the French government, through the UCAJEDI and EUR DS4H Investments in the Future projects managed by the National Research Agency (ANR) with the reference number ANR-15-IDEX-0001 and ANR-17-EURE-0004. The authors are grateful to anonymous referees of the scientific committee of the AIM 2021 for their insights, comments and suggestions. * Ce travail a été soutenu par le gouvernement français, à travers les projets UCAJEDI et EUR DS4H Investissements d'avenir gérés par l'Agence Nationale de la Recherche (ANR) sous les numéros de référence ANR-15-IDEX-0001 et ANR-17-EURE-0004. Les auteurs remercient les évaluateurs anonymes de la conférence AIM 2021 pour leurs commentaires et suggestions.

Date

Each blockchain expert has an overview of both projects "Xceed" and "SIM". An interview guide supported semi-directive interviews, structured around four main themes (Table 3).

Table 3: Main themes of semi-directive interviews

Primary data have been supplemented by secondary data, for which "multiple" data collection has been undertaken. Depending on the project or inter-organisational level analysed, different typologies of secondary data were collected. First, Symag and the Renault Software Lab are part of Smart IoT for Mobility. All experts interviewed are actively involved in the project, so the data collected in these exploratory interviews are combined with participant and nonparticipant observations [START_REF] David | Logique, épistémologie et méthodologie en sciences de gestion. VIIIème Conférence Internationale de[END_REF]. In total, the data collected during 8 multidisciplinary working meetings with researchers and industrialists, and 6 CoPil meetings attended by the authors. Both meetings were held from 3 rd October 2017 to 31 st December 2020, and the authors prepared detailed minutes. Second, for the purpose to expand our analysis about Renault inter-organisational blockchain activities and other projects around connected vehicles (e.g. Xceed), secondary data, such as official online news releases, public presentation slides and videos, and brief use case descriptions, was collected to complement primary sources collected throughout the series of semi-directive interviews. This empirical material helps us construct the evolution of blockchain-related activities and projects at the ecosystem level, and the role played by the technology.

Qualitative Content Analysis

In line with theory-building approaches, we develop 4 codes to organise the data: technology functionalities, benefits for coordination, institutional technology, and trust by technology. We used Nvivo (release 1.3.2) to code interviews and secondary data. Table 4 shows the coding system and gives a description and an example of each code.

main themes:

-General information about the interviewee (e.g., position, role, activities) and about the company (e.g., internal organisation, interest blockchain); -Description of the internal and external innovation context in which they work on BT; -Current technological, external and organisational factors affecting Blockchain investigation and adoption (e.g., current coordination between industrial partners); -Future perspective on the role of the technology in promoting collaboration (focus on trust through technology).


published or not. The documents may come

Competition between electronic attachment and solvation revealed thanks to radiolysis

Competition between electronic attachment and solvation revealed thanks to radiolysis

Sophie Le Caër NIMBE, UMR 3685 CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex, France; Email: sophie.le-caer@cea.fr A convenient way to generate charges (electrons and holes) in materials and to study their fate consists in using ionizing radiation. [START_REF] Le Caër | Water Radiolysis: Influence of Oxide Surfaces on H2 Production under Ionizing Radiation[END_REF] Indeed, ionizing radiation penetrates in the depth of the material, generating charge carriers. During this presentation, we will focus on the behavior of electrons. Once generated, they can either solvate or attach to the molecule(s) of interest. We will illustrate this competition between both processes by two recent examples and show how this affects subsequent reactions.

The first one is imogolite nanotubes. Two types of inorganic aluminosilicate nanotubes are studied: one is hydrophilic on its external and internal surfaces (IMO-OH) while the second has a hydrophobic internal cavity due to Si-CH3 bonds (IMO-CH3), the external surface remaining hydrophilic. Picosecond pulse radiolysis experiments evidence that the electrons are efficiently driven outward. For samples with very few external water molecules (around 1% of the total mass), quasi-free electrons are formed. They can attach to a water molecule, generating the water radical anion, which ultimately leads to dihydrogen. When more external water molecules are present, solvated electrons, precursor of dihydrogen, are formed. The attachment of the quasi-free electron to water is a very efficient process and accounts for the high H2 production at low relative humidities values. When the water content increases, the solvation of the electron is preferred. These latter species lead to H2 production, but in a lower extent than quasi-free electrons.

The second one is fluoroethylene carbonate (FEC). We have investigated the degradation mechanisms induced by irradiation in FEC, a cyclic carbonate, which is an additive commonly used in lithium-ion batteries. Picosecond pulse radiolysis experiments performed in neat FEC evidence that the FEC •-radical anion is directly formed by attachment of the quasi-free electron to FEC, the solvation of the electron being a minor channel. The same observation was also performed in propylene carbonate, a cyclic carbonate. This behavior is due to a high affinity of the solvent for the electron. [START_REF] Le Caër | Ultrafast Decay of the Solvated Electron in a Neat Polar Solvent: The Unusual Case of Propylene Carbonate[END_REF] However, when FEC is a solute and not the solvent, the FEC •-species is not observed. This latter species is no longer stabilized by the solvent, and linear radical anions are formed after ring cleavage. Reaction mechanisms are proposed to account for the formation of the various gases detected, which are mainly CO and CO2.


Confined water in aluminosilicate nanotubes: Structure, dynamics and importance of charge separation effects upon irradiation


Sourav Ghosh

Laurence Courthéoux

Sylvette Brunet

Patrick Lacroix-Desmazes

Annie Pradel

Etienne Girard
email: etienne.girard@ifpen.fr

Denis Uzio
email: denis.uzio@ifpen.fr

Hybrid CoMoS -polyaniline nanowires catalysts for hydrodesulfurisation applications

Keywords: CoMoS catalyst, nano-hybrid, hydrodesulfurisation, olefins hydrogenation, polyaniline Highlights

Liquid and gas phase sulfidation conditions of MoOx/PANI hybrids result in different MoSx phases • Active CoMoS phase content in the final catalysts deposited through a surface reaction using cobalt acetylacetonate depends on the nature of starting Mo based PANI materials. The formation of mixed sites is favored when Mo and Co sulfidations are simultaneous. • CoMoS/PANI showed much better catalytic activities than the CoMoS counterpart prepared without PANI • HDS of 3-methylthiophene is correlated to the Co/Moedges+corners atomic ratio as well as the HDS / HYD selectivity factor.

Introduction

In the recent decades, worldwide regulations of fuels combined with the processing of heavier hydrocarbon resources as well as the increase of the global energy demand have driven the development of evermore active hydrotreatment catalysts. For instance, production of "sulfur free" gasoline (less than 10 ppm since 2009) has received significant attention over the years and still is a hot topic of environmental catalysis [1,2]. Conventional hydrotreatment catalysts are made of nanometer-sized molybdenum or tungsten sulfide slabs supported on oxidic carriers, where the edge sites of the slabs promoted by nickel or cobalt are considered as the active sites [START_REF] Toulhoat | Catalysis by transition metal sulphides. From molecular theory to industrial applications[END_REF]. However, these supported catalysts suffer strong limitations when high metal loadings combined with high active phase dispersion are targeted. So far, in order to improve the catalytic performances, many studies have focused on modification of supports by addition of organic [1,[START_REF] Toulhoat | Catalysis by transition metal sulphides. From molecular theory to industrial applications[END_REF][START_REF] Tanimu | [END_REF][5][6][7][8] and inorganic additives [1,[START_REF] Toulhoat | Catalysis by transition metal sulphides. From molecular theory to industrial applications[END_REF][START_REF] Tanimu | [END_REF]6,[9][10][11], type of supports [1,[START_REF] Toulhoat | Catalysis by transition metal sulphides. From molecular theory to industrial applications[END_REF][START_REF] Tanimu | [END_REF]6,[12][13][14], and active phase modifications [1,[START_REF] Toulhoat | Catalysis by transition metal sulphides. From molecular theory to industrial applications[END_REF][START_REF] Tanimu | [END_REF]6,[15][16][17][18][19]. Nowadays, a breakthrough in terms of activity seems difficult to achieve through these strategies and the alternative way could be the development of unsupported bulk sulfide catalysts to drastically increase the active phase content per volume and the performances accordingly [1,20,21].

Typical synthesis of bulk unsupported samples consists in thermal decomposition or (co) precipitation of (oxo)thio salts under various experimental conditions [6,[22][23][24][25][26][27]. However, these approaches are often not suitable to achieve highly efficient catalysts since a large fraction of the metallic sites does not participate to the reaction due to a poor accessibility. Moreover, a nanoscale control of the bimetallic composition is difficult to achieve on bulk catalysts. Hence, in order to prepare an optimized catalyst, the control of the individual slabs properties at the nanoscale is mandatory to maximize the intrinsic activity and as well as the control of their mesostructure for active site accessibility and diffusion purposes. These considerations have been addressed in previous reports playing on synthesis methods of bulk CoMoS catalysts for FCC gasoline hydrodesulfurisation. Zhang et al. have reported that the slab size and stacking of MoS2 could be tuned under hydrothermal conditions by changing the pH and precursors, which in turn determine the HDS selectivity in of FCC gasoline [28]. In a different report, Li et. al. demonstrated that unsupported Co-Mo catalysts prepared using ion-exchange reaction of cobalt carbonate hydroxide as precursor followed by a gas-phase sulfidation, exhibit higher HDS selectivity for both model molecule and full-range FCC gasoline than supported CoMo/γ-Al2O3. The improvement was explained in terms of slab length, number of layers and curvature of the slabs [29]. Concerning this last feature, Afanasiev et al have shown that inorganic "fullerene-like" structures of MoS2 (onion-like or hollow MoS2) are active towards thiophene HDS and the curved and/or broken basal planes are found to exhibit high activity. [30,31].

In order to achieve a high dispersion and accessibility of active phases, template-assisted synthesis has been carried out using soft and hard templates for the synthesis of bulk mesostructured metal sulfide catalysts [START_REF] Tanimu | [END_REF]6,23]. Several organic templates including surfactants (ionic and non-ionic) and polymers (polyethylene glycol, pluronic 123 (P123), polyvinylpyrrolidone (PVP), etc) have been extensively used as soft template for synthesis of high surface area unsupported bulk catalysts [6,23,[32][33][34][35]. In order to control the physicochemical properties (size, aggregation, and accessibility/orientation), electronic properties of the active sites, synthesis of MoS2 using a polymer as a template recently appeared as a promising alternative [23]. Similarly, bulk unsupported catalysts were also synthesized using the hard template route [6,[36][37][38]. However, many challenges still exist to improve bulk HDS catalysts features such as an optimum dispersion and accessibility of the edge sites to reactants / products, sintering resistance for deactivation issues, control of the promotion at high metal loading and control of the assembling of individual slabs for mass transfer properties. It can be also noticed that this type of catalysts suffer from a lack of studies compared with supported counterparts.

The present work gets inspired by the design of MoS2/PANI (Polyaniline) hierarchical nanostructures for lithium-ion batteries wherein, the nanoscale dimension of MoS2 promotes the kinetics of Li + ion storage due to the shortened diffusion paths, while PANI nanowires effectively avoid aggregation of the active nano slabs and ease the transport of electrons and ions [38]. Applied to HDS reaction, the unique arrangement of the MoS2 slabs at the surface is supposed to favor the exposure of more active edges to reactants. The work presented in this manuscript will therefore focus on the synthesis of bulk promoted (Co)MoS2 catalysts via polymerisation induced self-assembly, using polyaniline as a nucleating-growth agent for molybdenum sulfide slabs (Figure 1). In particular, different routes for the formation of the promoted CoMoS phase have been investigated adding Co on MoOx/PANI oxidic phase or on MoSx/PANI sulfide one. The characterizations of the solids by scanning and transmission electron microscopy (SEM/TEM), as well as Raman and X-Ray photoelectron (XPS) spectroscopies will be presented and discussed in relation with the catalytic performances in selective HDS.

Experimental

Synthesis -Materials

Aniline, thioacetamide, ammonium heptamolybdate ((NH4)6Mo7O24•4H2O), cobalt acetylacetonate (Co(acac)2•2xH2O) and ammonium persulfate ((NH4)2S2O8) were purchased from Sigma Aldrich. Hydrochloric acid (HCl), methanol, acetone and ethanol were obtained from VWR International. All analytical grade chemicals were used as received until specified.

All the reaction were carried out using a doubly distilled water obtained from a Millipore system. γ-Alumina used for dilution was provided by Axens.

-Synthesis of Mo3O10(C6H8N)2•2H2O nanowires

The synthesis of Mo3O10(C6H8N)2•2H2O molecular precursor and the subsequent polymerisation step are adapted from the literature [38]. Typically, 7.44 g (6 mmol) of (NH4)6Mo7O24•4H2O (M = 1235.86 g/mol) was dissolved in 120 mL of water. Then 10.02 g (107.6 mmol) of aniline (M=93.13 g/mol) was added (aniline:Mo = 2.5:1 molar ratio) .

Subsequently, 1M HCl aqueous solution was added under vigorously stirring condition at 30°C until a white precipitate appeared (pH=4-5). The reaction mixture was stirred at 50°C for 2 h.

The white product of Mo3O10(C6H8N)2•2H2O nanowires was filtered and washed one time with water and three times with ethanol and dried under vacuum at 50°C for 6 h.

-Synthesis of MoOx/PANI 0.68 g (1 mmol) of Mo3O10(C6H8N)2•2H2O (M= 672.17 g/mol), 0.538 g (0.435 mmol) of (NH4)6Mo7O24•4H2O and 1.14 g (5 mmol) of (NH4)2S2O8 (M=228.20 g/mol) were added in 80 mL of water, and the pH was adjusted to 2 by adding 5mL of a 1M HCl aqueous solution. After vigorously stirring at 30°C for 6 h, the dark green precipitate of MoOx/PANI was filtered and washed four times with water and ethanol and dried under vacuum for 6 h at 50°C.

-Sulfidation of MoOx/PANI

• Liquid-phase sulfidation at 80°C At first, 3 g of MoOx/PANI was dispersed in 60 mL of aqueous HCl solution (pH=1) and the solution was heated up to 80°C. Then, 3 g (40 mmol) of thioacetamide (M=75.13 g/mol) (S:Mo~3:1 molar ratio) was added in the reaction mixture and vigorously stirred for 3 h at 80°C. After naturally cooling, the black precipitate was filtered and washed four times with water and ethanol and dried under vacuum for 6 h at 50°C. The MoSx/PANI powder was stored under an argon filled glove box. The sample was abbreviated as MoSx/PANI_thioA.

• Gas-phase sulfidation at 350°C

An aliquot of the MoOx/PANI was sulfided in gas-phase sulfo-reductive conditions (H2S/H2 15:85 v/v) at atmospheric pressure. Firstly, MoOx/PANI powder was transferred in a quartz reactor and heated 2 h at 350°C (heating ramp 5°C min -1 ) under H2S/H2 constant flow (2 Lh -1 g - 1 ). After the plateau, the reactor was cooled down naturally under the flow of H2S/H2 mixture, which was replaced at 50°C by argon during 10 min. Finally, the reactor was evacuated (∼1 mbar) and transferred inside an argon filled glove box. The sample was named as MoSx/PANI_H2S.

-Cobalt promotion step the molybdenum phases

The promotion step with cobalt acetylacetonate Co(C5H7O2)2.2H2O (257.15 g/mol) under reflux conditions was carried out following the procedure developed by Bezverkhyy et al. [39] In a typical synthesis, required amount of Co(C5H7O2)2.2H2O (Co:Mo=0.4 mol:mol) was dissolved in a minimum amount of degassed methanol and then the catalyst (MoOx/PANI or MoSx/PANI) was added and the reaction mixture was refluxed at 30°C for 18 h under Ar atmosphere. After that, methanol was evaporated and the solids were dried under vacuum at 50°C for 6 h. In order to improve the chemical interaction with the MoOx/PANI surface, we modified this protocol by heating at 65°C for 4 h during Co(acac)2 impregnation, removing the excess of unreacted Co by filtration/washing and finally drying under vacuum for 6 h at 50°C.

Characterizations before catalytic tests

Powder X-ray diffraction (XRD), CHNS elemental analysis, X-Ray fluorescence (XRF), Fourier transformed infrared (FTIR) and Raman spectroscopies, SEM, and N2 physisorption measurements were carried out on the different samples before Co addition. After Co deposition, samples were further characterized by powder XRD, CHNS elemental analysis and XRF. The details of these experiments are available in the SI.

Catalytic tests

All the catalysts were diluted with high surface area γ-Al2O3 (SBET = 265 m 2 g -1 ). The γ-Al2O3 extrudates were grinded using a ball mill, the powder was sieved and the fraction below 64 μm was collected for a better mixing with the catalyst. The Al2O3 powder was mixed with the catalyst in order to achieve 10 wt% equivalent MoO3 loading in the final solid (γ-Al2O3+catalyst) and the mixture was further ball milled (3 min, 25 Hz). Afterwards, the powder was pelletized and sieved to collect the 0.355-1.25 mm fraction. This fraction was used for the catalytic tests.

HDS

𝑘 𝐻𝐷𝑆 𝑜𝑟 𝐻𝑌𝐷 = 𝐿𝐻𝑆𝑉 % 𝑀𝑜𝑆 2 𝑒𝑑𝑔𝑒𝑠 + 𝑐𝑜𝑟𝑛𝑒𝑟 * ln ( 1 1 -𝑥 𝐻𝐷𝑆 𝑜𝑟 𝐻𝑌𝐷 ) (2)
Here, x is the HDS of 3-MT or hydrogenation (HYD) of 2,3-DM2BN. Normalization by (MoS2)edges+corner loaded in the reactor was made using XPS and TEM results applying the hexagonal geometric model for MoS2 sulfide slabs [40].

Results and discussion

Characterization of unpromoted samples

Figure 2 shows the SEM images of MoOx/PANI, MoSx/PANI_thioA, and MoSx/PANI_H2S.

Nanowire morphologies with diameters ranging between 100-500 nm and length between 5 to 20 μm are distinguishly observed in the three samples (Figure S1); the morphological data are comparable to the ones reported in the literature [38] showing the good reproducibility of the synthesis. All three samples present a granular aspect corresponding to Mo based particles homogeneously distributed on the surface of the nanowires. Nevertheless, a mode disordered structure can be observed in the case of MoSx/PANI_H2S likely due to the partial decomposition of PANI nanorods. In order to identify the structure of MoOx/PANI and MoSx/PANI, powder XRD analysis was carried out (Figure 3). The pattern of the MoOx/PANI looks like an amorphous molybdenum oxide. The diffraction peak (d-spacing 1.32 nm) is shifted at lower 2θ value indicative of the intercalation of PANI into the amorphous MoOx layers as reported in literature [38] The cm -1 (C=C stretching) [42]. After reflux sulfidation with thioacetamide at 80°C (MoSx/PANI_thioA), the Raman bands correspond to PANI are preserved and a new set of broad peaks appears at 160 and 220-230 cm -1 (corresponding to the Mo-S in-plane bending modes), 310-390 and 450 cm -1 (for the Mo-S stretching modes), and 520-555 cm -1 (S-S stretching modes). This could be attributed to the formation of MoS3 and was further matched with standard MoS3 [43,44]. On the other hand, MoSx/PANI_H2S obtained after gas-phase sulfidation at 350°C, has two Raman active bands located at 383 (E2g) and 405 cm -1 (A1g), which can be attributed to the crystalline MoS2 phase [43]. Moreover, Raman bands for PANI were not observed anymore due to thermal decomposition at high temperature in agreement with CHNS results. Assuming the missing material from the CHNS analysis comes from residual oxygen combined to Mo to form MoO3, and removing this contribution for the calculation of S/Mo ratio, 1.9 and 2.9 values corresponding to MoS2 and MoS3 are found respectively for MoSx/PANI_H2S and MoSx/PANI_thioA in good agreement with Raman and XRD results.

diffraction
Roughly, 15% of Mo is still oxidized in MoSx/PANI_thioA (resp. 8% for MoSx/PANI_H2S).

MoOx/PANI and MoSx/PANI samples were further characterized by FTIR spectroscopy (Figure S4). The spectral band assignments corresponding to the molybdates, molybdenum sulfides and PANI are discussed After reflux sulfidation at 80ºC, the relative intensity of the peak observed at 975 cm -1 peak corresponding to the molybdate species decreased, while the absorption bands corresponding to PANI remained almost similar to the parent MoOx/PANI.

On the other hand, the absorption bands corresponding to PANI and molybdate species completely vanished after gas phase sulfidation at 350ºC, due to the degradation of PANI and high sulfidation degree of molybdates at 350ºC. Finally, TGA analysis has been performed to assess the stability of the MoOx/PANI and MoSx/PANI_thioA samples (Figure S3 in supporting information). For both samples, the cumulative weight loss until 350°C is similar and close to 12%. This result confirms the good stability of the structures during the catalytic experiments as observed on the spent catalysts by microscopy. This allows us to discard a deep decomposition of the solid in the operating conditions of the catalytic test.

Characterization of promoted catalysts

MoOx/PANI, MoSx/PANI_thioA and MoSx/PANI_H2S samples were used as parent solids for the promotion step with cobalt acetylacetonate under different conditions. Bezverkhyy et. al.

have shown that using cobalt acetylacetonate in organic solvents led to more active CoMoS phases than Co(NO3)2.6H2O due to the incorporation of cobalt into sulfided Mo after treatment with cobalt acetylacetonate [39] as shown by EXAFS. Over the years, other groups have established the importance of these promotion methods for alumina and carbon supported MoS2 catalysts [45]. Table 3 summarizes the elemental analysis after the promotion step.

Interestingly, the Co/Mo molar ratios are very close and correspond to the targeted values. Total metal amount (Mo+Co) in the range of 40-50 wt % are typical of conventional bulk catalysts and well above those of supported counterparts. We can also notice that CoMoOx/PANI_65 contains less Co in agreement with the synthesis protocol including a washing step for the removal of unreacted Co precursors.

Generally speaking, no significant change in the CHNS contents with respect to the parent samples were noticed after the promotion step. Additionally, no visible change of the mesoscale morphologies was observed after Co(acac)2 deposition as shown on SEM images (see Figure S5 for the CoMoOx/PANI_65 as an example). as well as for the BET surface areas not reported here but not significantly modified. Similarly, no structural changes after promotion by Co were observed on powder XRD patterns (see Figure S6).

Catalyst characterization after catalytic tests

For convenient reasons, the labelling containing "MoOx" was kept even if the spent catalysts are under their sulfided state and characterized by XPS and TEM as such.

-X-Ray photoelectron spectroscopy (XPS)

The decomposition of the S 2p, Mo 3d and Co 2p XPS spectra were performed using the corresponding oxide and sulfided references as supported monometallic catalysts and the decomposition methodology of CoMo/Al2O3 spectra set up by Gandubert et al. [46] The relative compositions are tabulated in Table 4. Concerning the Co analysis, all the catalysts contain almost the same amount of Co at the surface except the CoMoOx/PANI_65 (1.1% instead of 2-3 %) due to the removal of excess Co during the washing step. The highest content is observed for CoMoSx/PANI_thioA_30. This tendency is in agreement with XRF results presented in Table 3. Co +2 (CoO), cobalt sulfide noted "CoSx " but mainly under Co9S8 and catalytically active CoMoS phase were observed (Figure 5b). Among all the promoted catalysts, CoMoOx/PANI_65 contains the highest fraction (CoMoSx/PANI_thioA_30) > MoS2 (CoMoSx/PANI_H2S_30). This result is supported by the fact that the formation of mixed phases is favored when the sulfiding process occurs simultaneously for both metals Mo and Co [47], which qualitatively follows the same order.

Cobalt acetylacetonate addition in the synthesis conditions as described in this paper is therefore less effective on a sulfided Mo phase than oxidic Mo phase likely due to weaker interactions with surface sites.

The binding energy values of Mo after deconvolution for all the promoted catalysts are given in Table S1. Among all these promoted catalysts, no major shift in Mo3d5/2 peak positions was observed (+/-0.3 experimental error). Interestingly, it was observed that surface Mo (wt%) concentrations measured by XPS are lower for PANI catalysts than the global Mo (wt%) concentrations obtained from XRF analysis. On the other hand, trends for Co (wt%) concentrations are found to be opposite i.e., higher surface Co concentrations are observed with respect to the global Co concentration. Since cobalt precursors are added after the polymerization process, the cobalt atoms remain mainly localized at the surface of the nanowires without encapsulation by carbon as in the case of a fraction of Mo. All the PANI assisted synthesis led to a much lower mean size and stacking of MoS2 slabs compared to the reference CoMoS catalyst prepared without PANI, thus showing its beneficial effect on the stabilisation against sintering, growth and aggregation. Among the PANI containing catalysts, CoMoOx/PANI_65 exhibits the lowest average slab length and stacking values. This may be due to the different operating conditions during the Co addition (i.e. higher temperature) suggesting an influence of the temperature of Co impregnation on the final MoS2 crystal size. We may hypothesize a partial dissolution and redispersion of MoOx by some released acacH moieties coming from the reaction of Co(acac)2 through a dissociative adsorption with the MoOx surface by analogy with the results in ref [39]. +1 with ni : number of Mo atoms along one side of a MoS2 slab determined from its length and i being the total number of slabs measured by TEM.

Catalytic activity of promoted samples

Catalytic activities of promoted catalysts were evaluated under selective HDS conditions using 8c) shows a classical behavior with an increase of HYD activity with HDS activity without large discrepancies between the catalysts, the highest selectivity being observed for CoMoOx/PANI_65. Plotting the selectivity ratio versus the (Co/Mo)edges+corner atomic ratio defined as the ratio between (Co/Mo)slab and dTEM ratio 1 seems to follow a maximum curve (Figure 8d). This result is in agreement with literature since it is usually reported that the promoter impacts much more HDS than HYD. As a consequence, the selectivity factor is supposed to follow the shape of the HDS curve versus the promoter content [2].

Plotting the normalized HDS rate constants (by mol of (MoS2)edges+corner) versus the (Co/Mo)edges+corner atomic ratio, a clear correlation for the different catalysts is observed (Figure

). Actually, the rate constant per mol (MoS2) edges+corner, which actually corresponds to a Turn Over Frequency (TOF), follows the (Co/Mo)edges+corner atomic ratio. Interestingly, this promotion effect is more pronounced on HDS when temperature increases (higher than 200°C) and for values higher than circa 0.9. This may be qualitatively supported by previous works on the influence of Co/Mo ratio and the ability to form active mixed sites by increasing the Co coverage of edges [48] as well as on the Mo-S bond strength and as a consequence on the catalytic activity [49,50].

Figure 1 :

 1 Figure 1 : Schematic representation of the preparation of nanohybrid CoMoS catalysts embedded with polyaniline self-assembled nanowires.

Figure 2 .

 2 Figure 2. Effect of sulfidation conditions on morphology; SEM images of a) MoOx/PANI, b) MoSx/PANI_thioA, and c) MoSx/PANI_H2S.

  pattern for MoSx/PANI_thioA synthesized at 80°C exhibits a broad peak at 14° attributed to the formation of amorphous MoSx. The crystallinity of the molybdenum sulfide is improved upon gas-phase sulfidation at 350°C and the diffraction peak of MoSx/PANI_H2S matches with hexagonal MoS2 (ICDD: 04-008-2232; 2θ = 14°, 33.5° and 58.8° correspond to the respective (002), (100) and (110) lattice planes of MoS2).

Figure 3 .Figure 4 .

 34 Figure 3. Powder XRD pattern of MoOx/PANI, MoSx/PANI_thioA, and MoSx/PANI _H2S.

Figure 4 .

 4 Figure 4. Raman spectra of reference MoS3, reference PANI, MoOx/PANI, MoSx/PANI_thioA, and MoSx/PANI_H2S, plotted in the range of a) 100-1000 cm -1 and b) 100-2000 cm -1 Raman shift.

  The Mo concentration of the PANI catalysts are quite similar (≈ 4 wt%) and lower than the reference due to a fraction of embedded Mo in the PANI matrix. Three different oxidation states of Mo, i.e. Mo +4 , Mo +5 and Mo +6 are detected which could be assigned to the MoS2, molybdenum oxysulfide (MoOxSy) and molybdenum oxide (MoOx) phases respectively (Figure5aand FiguresS7-9in Sup Inf). XPS analysis shows that the main contribution corresponds to the desired phase Mo IV (MoS2) around 74-77% for the samples sulfided in liquid phase and higher (85%) for the CoMoSx/PANI_H2S_30 sulfided in gas phase, close to the ref CoMoS (89%) also sulfided in gas phase. The gas phase sulfidation thus allows a higher reduction of Mo V (oxysulfide MoOxSy) into Mo IV (MoS2).

Figure 5 :

 5 Figure 5: Spectral decompositions of high resolution a) Mo 3d and b) Co 2p (2p3/2 region of the spectrum) core level spectrum of CoMoOx/PANI_65 chosen as an example (spent sulfided catalyst).

of

  Co as CoMoS phase (51%) with a low content of inactive CoSx (20.1%) thus showing the beneficial effect of the removal of unreacted Co precursors on the formation of promoted mixed sites. Unreacted Co(acac)2 is prone to form unreactive CoSx during the gas phase sulfidation step. On the other hand, CoMoSx/PANI_H2S_30 exhibits a low CoMoS (14%) phase content associated with a low (Co/Mo)slab ratio. In our experiments, it can be stated that the nature of the unpromoted starting solid (i.e. oxidic amorphous sulfide as MoS3 or crystallized as MoS2) and synthesis conditions (i.e. washing step), affect the fraction of Co under CoMoS phase according the following sequence: MoOx (CoMoOx/PANI_65 > CoMoOx/PANI_30) > MoS3

2 -Figure 6 :

 26 Figure 6: TEM images of the different spent catalysts.

Figure 7 :

 7 Figure 7: Slabs length distribution for the different spent catalysts.

3-methylthiophene ( 3 -Figure 8 .

 38 Figure 8. The apparent activation energies for HDS of 3-MT of all the promoted catalysts were around 22-35 kcal/mol, whereas for HYD of 2,3-DM2BN values in the range 20-32 kcal/mol were determined. From these data, it can be considered that the catalytic reactions fall in the chemical regime. The HDS and HYD rate constant of CoMoSx/PANI_thioA_30 are the highest ones followed by those of CoMoOx/PANI_30 whereas the two other catalysts gave performances very close to the reference CoMoS catalyst. Selectivity graph (selectivity factor kHDS/kHYD versus kHDS) (Figure

Finally, HDS performancesFigure 8 :

 8 were assessed in a real gas-oil feedstock composed of straight-run gas oil (SRGO) and light cycle oil (LCO) containing 6815 ppm S. At 330°C, a total pressure of 40 bar and after 130 h of stabilization, CoMox/PANI_30 exhibited 95% of the activity expressed per mol Mo of an industrial Al2O3 supported CoMo catalyst and showed an 180% increase in the volumetric activity. This preliminary result is highly encouraging for the development of structured bulk hydrotreating catalysts. a) Normalized HDS rate constants (kHDS) versus temperature, b) normalized HYD rate constants (kHYD) versus temperature, c) kHDS/kHYD ratio versus kHDS d) selectivity factor slab (XPS) / d TEM (kHDS/kHYD) versus the (Co/Mo)edges+corner atomic ratio at a constant HDS conversion of ≈ 30% for the different catalysts.

Figure 9 :

 9 Figure 9: Normalized HDS rate constants kHDS versus the (Co/Mo)edges+corner atomic ratio at different temperatures.

Table 1

 1 summarizes the different preparations.

Table 1 :

 1 Abbreviation and synthesis conditions of the different samples.

catalyst Synthesis condition Unpromoted MoOx/PANI Mo3O10(C6H8N)2•2H2O, (NH4)2S2O8, (NH4)6Mo7O24•4H2O, water; pH=2, 30°C, 6 h stir MoSx/PANI_thioA MoOx/PANI, thioacetamide (Mo:S=1:3 mol/mol), water; 80°C, 3h stir, pH=1 MoSx/PANI_H2S MoOx/PANI; 15:85 v/v H2S:H2, 350°C, 2 h Promoted CoMoOx/PANI_30 MoOx/PANI, Co(acac)2, methanol; 30°C, 18 h stir (Ar) CoMoSx/PANI_thioA_30 MoSx/PANI_thioA, Co(acac)2, methanol; 30°C, 18h stir (Ar) CoMoSx/PANI_H2S_30 MoSx/PANI_H2S, Co(acac)2, methanol; 30°C, 18 h stir (Ar) CoMoOx/PANI_65 MoOx/PANI, Co(acac)2, methanol; 65°C, 4 h stir (Ar) filtration/washing Ref CoMoS * MoSx_H2S, Co(acac)2, methanol; 30°C, 18 h stir (Ar) *: details for the synthesis of the Ref CoMoS catalyst are given in the SI

Table 2 .

 2 Elemental and textural analysis of unpromoted samples.

	Samples	SBET	Elemental analysis	XRF
		(m 2 /g)		wt %	wt%
			C	H	N	S	Mo
	MoOx/PANI	8	18.2 2.6 3.7	-	38.7

Table 3 .

 3 XRF and CHNS elemental analysis of the promoted samples (before catalytic test).

	Samples	Elemental analysis wt% C H N S	XRF wt% Mo Co	Co:Mo mol/mol	S:Mo mol/mol
	CoMoOx/PANI_30	17.8 2.4	3.7	-	31.9 8.1	0.4	-
	CoMoSx/PANI_thioA_30 17.0 1.8	3.8	34.6 31.0 7.2	0.4	3.3
	CoMoSx/PANI_H2S_30	5.7	< 1 0.6	36.6 40.3 8.7	0.4	2.7
	CoMoOx/PANI_65	24.8 2.8	4.5	-	31.9 5.6	0.3	-

Table 4 .

 4 XPS analysis results of the spent (sulfided) catalysts.

	Catalysts	At. Ratio Co/Mo slab*	% wt Mo %wt Co	Mo species (% relative) MoS2 MoOxSy Mo +6	Co species (% relative) CoMoS CoSx Co +2
	CoMoOx/PANI_30	0.25	3.8	2.1	75.9	11.3	12.8	21.1	37.2	41.7

Table 5 :

 5 Average slab lengths, fractions of Moedge+corner (dTEM), and average stacking values of the spent (sulfide) samples.

	Mo 𝑒𝑑𝑔𝑒𝑠+𝑐𝑜𝑟𝑛𝑒𝑟 𝑀𝑜 𝑡𝑜𝑡𝑎𝑙	=	∑ 6n 𝑖 -6 𝑖 ∑ 3𝑛 𝑖 2 -𝑖 3n 𝑖

* dTEM:

atomic ratios (promotion factor) whereas an optimum versus the same ratio was observed for the HDS/HYD selectivity factor. In perspective of this work, the overall intrinsic catalytic activity of these bulk promoted catalysts could be further improved via an optimization of the nature of active sites (i.e. promotion level) or a gain in active phase accessibility playing with the dimensions, self-assembly properties or morphology of PANI structures.

Acknowledgments

The authors thank the Agence Nationale de la Recherche (ANR) for research project grant (ANR PASSCATA -ANR-16-CE07-0029). Authors also thank Virgile Rouchon, Veronique Lefebvre (IFPEN) and Julie Rousseau (IC2MP) for their assistance with the TEM data recording, Saloua Sahal-El-Ahrache, Christele Legens and Laurent Lemaitre (IFPEN) for XPS analysis.