Advanced carbon materials as electro-catalyst supports for fuel cells application

The electro-catalytic materials used at the electrodes of low temperature fuel cells play a key role in determining the performance, stability and cost-effectiveness of the system. Noble metals are generally used to lower the overpotential of the half-reactions. To maximize the utilization of these precious metals, they are supported on carbon materials in the form of small nanoparticles (2-3 nm). Carbon materials should present a good electrical conductivity, a high surface area, an open porous structure (mesopores are preferred) and a good resistance to electrochemical corrosion. Recent studies have revealed that carbon supports can not only provide a high dispersion of Pt nanoparticles, but also facilitate the electron transfer processes, affecting positively the fuel cell performance [1]. Novel non-conventional carbon materials have attracted a great interest as electrocatalyst support, including graphene, carbon nanotubes, carbon nanofibers, carbon nanocoils, carbon nanospheres, carbon aerogels, carbon xerogels, ordered mesoporous carbons, etc. The wide variety of carbon morphologies and the possibility to tune their porosity and surface chemistry opens a broad spectrum of possibilities to optimize the performance of fuel cell catalysts. Due to corrosion phenomena in carbon, also non-carbon supports are investigated, such as stable metal sub-oxides. The main problems regard their relatively low surface area and electrical conductivity when compared to commonly used carbon supports. In this contribution we will present recent results regarding the utilization of advanced supports for noble metals and the effect of the support features on activity and stability [2-7]. 1. E. Antolini, Applied Catalysis B: Environmental 1-2, 1 (2009). 2.D. Sebastián, A.G. Ruiz, I. Suelves, R. Moliner, M.J. Lázaro, V. Baglio, A. Stassi, A.S. Aricò, Applied Catalysis B: Environmental 115-116, 269 (2012). 3.D. Sebastián, M.J. Lázaro, I. Suelves, R. Moliner, V. Baglio, A. Stassi, A.S. Aricò, International Journal of Hydrogen Energy, 37, 6253 (2012). 4.D. Sebastián, I. Suelves, R. Moliner, M.J. Lázaro, A. Stassi, V. Baglio, A.S. Aricò, Applied Catalysis B: Environmental 132-133, 22 (2013). 5.C. Alegre, D. Sebastián, M.E. Gálvez, R. Moliner, A. Stassi, A.S. Aricò, M.J. Lázaro, V. Baglio, Catalysts 3, 744 (2013). 6.D. Sebastián, M.J. Lázaro, R. Moliner, I. Suelves, A.S. Aricò, V. Baglio, International Journal of Hydrogen Energy 39, 5414 (2014). 7.D. Sebastián, C. Alegre, M.E. Gálvez, R. Moliner, M.J. Lázaro, A.S. Aricò, V. Baglio, Journal of Materials Chemistry A 2, 13713 (2014).