Cycle durability of metal oxide supports for PEFC electrocatalysts

In order to develop durable electrocatalysts for polymer electrolyte fuel cells, six different metal oxides, namely MoO3, SnO2, Nb2O5, Ta2O5, TiO2, and WO3, are selected as thermochemically stable, carbon-free platinum electrocatalyst support materials. The stability of Pt on these alternative oxide support materials is systematically analyzed, for the first time, using common experimental protocols simulating realistic fuel cell vehicle operation. Pt/SnO2 shows the best performance in terms of both electrochemical activity, and stability against dissolution. Pt dissolution rates in Pt/SnO2 are comparable to those of conventional Pt/C electrocatalysts. These results suggest that SnO2 is a promising candidate as an alternative electrocatalyst support.