Environmentally friendly recycling of fuel cell's membrane electrode assembly using ionic liquids

Abstract : The platinum nanoparticles used as catalyst in Proton Exchange Membrane Fuel Cells (PEMFCs) represent around 46% of the cells total price and is one of the limitations for their large scale commercialization. The recycling of the platinum catalyst represents a good way to limit the production cost of PEMFCs. Usual recovery routes for platinum-containing catalysts are pyro-hydrometallurgical processes, combining a calcination step and an aqua regia treatment, generating fumes and NOx emission. An electrochemical recovery route by coupling electrochemical leaching and electrodeposition in ionic liquids (ILs) is proposed here, more environmentally friendly, performed in "soft" temperature conditions and without any gases emission. Imidazolium chloride ILs were selected for their complexing ability against platinum and their good electrochemical stability. They were used either pure or diluted in a low coordinating IL, BMIMTFSI (1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide). The electroleaching of massive platinum was first studied in several chloride-based ILs. BMIMCl (1-butyl-3-methylimidazolium chloride) appeared to be the best of leaching media tested, as passivation phenomena were observed in other ILs. BMIMCl + BMIMTFSI melts were then tested, containing different BMIMCl amounts. A marked increase of the leaching rate with BMIMCl content is observed up to 0.1 M. For contents higher than 0.5 M, the leaching rate is comparable with the one obtained in pure BMIMCl. The study of the electrochemical recovery of leached platinum revealed that its electrodeposition is impossible in the electrochemical window of pure BMIMCl, due to its high chloride content. On the contrary, platinum electrodeposition was successful in BMIMCl + BMIMTFSI ILs melts for BMIMCl content up to 0.1 M. ILs melts were then successfully used for platinum recovery from fuel cell electrodes. By further modulating the composition of the melt and the electrode potential control mode, it also appeared possible to simultaneously leach and electrodeposit platinum in a single cell process.
Type de document :
Communication dans un congrès
2nd Green & Sustainable Chemistry Conference, May 2017, Berlin, Germany
Domaine :
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https://hal.univ-lorraine.fr/hal-01494647
Contributeur : Sophie Legeai <>
Soumis le : jeudi 23 mars 2017 - 17:35:29
Dernière modification le : mardi 21 août 2018 - 09:46:03

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  • HAL Id : hal-01494647, version 1

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Maxime Balva, Sophie Legeai, Nathalie Leclerc, Emmanuel Billy, Eric Meux. Environmentally friendly recycling of fuel cell's membrane electrode assembly using ionic liquids. 2nd Green & Sustainable Chemistry Conference, May 2017, Berlin, Germany. 〈hal-01494647〉

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