Cathodic performance and high potential durability of Ta-SnO2-δ-supported Pt catalysts for PEFC cathodes

We evaluated the cathodic activity and durability of Pt/Ta-SnO2-delta catalysts for the cathodes of polymer electrolyte fuel cells (PEFCs). The Ta-SnO2-delta support had a unique fused aggregated structure, for which the electrical conductivity was ca. 40 times higher than that of another candidate high-durability support, Nb-SnO2-delta with the same support structure. The kinetically controlled current density value at 0.85 V for Pt/Ta-SnO2-delta reached 0.97 mA cm(-2), which was higher than that for a commercial Pt/CB. Chemical stability of Ptfra-SnO2-delta in the high potential range (0.9-1.3 V) was the same as that of the high-durability Pt/Nb-SnO2-delta catalyst and was superior to that of commercial Pt/CB and Pt/GCB. We demonstrated that the more highly electrically conductive Pt/Ta-SnO2-delta is an attractive catalyst for the construction of low-resistance catalyst layers of membrane-electrode assemblies with decreased overpotentials. Thus, we conclude that the Pt/Ta-doped SnO2-delta catalyst is a superior cathode candidate catalyst for PEFCs. (C) 2014 Elsevier B.V. All rights reserved.