Synthesis and electrochemical characterization of Pt catalyst supported on Sn0.96Sb0.04O2−δ with a network structure

We synthesized a Pt catalyst supported on Sn0.96Sb0.04O2−δ with a random network structure for the cathode of the polymer electrolyte fuel cell (PEFC). The Sn0.96Sb0.04O2−δ support, synthesized by the flame combustion method, was in the form of nanometer-sized particles with a partially agglomerated structure similar to that of carbon black (CB) and with a high surface area, 125 m2 g−1. The structure was considered to be beneficial in reducing the contact resistance between the Sn0.96Sb0.04O2−δ support particles and in dispersing the nanometer-size Pt particles. We applied the nanocapsule method to synthesize the Sn0.96Sb0.04O2−δ-supported Pt catalyst (Pt/Sn0.96Sb0.04O2−δ). The electrochemically active surface area (ECA) of Pt reached a maximum of 60.2 m2 g(Pt)−1, and the high values were maintained during the potential step cycling test (0.9-1.3 V) simulating the start/stop cycling of PEFCs. The oxygen reduction reaction activity of the Pt/Sn0.96Sb0.04O2−δ catalyst exceeded that of Pt supported on carbon black (Pt/CB). We conclude that the random network structured Sn0.96Sb0.04O2−δ might be a good candidate support material for the cathode of PEFCs.