Improved Electrocatalytic Oxygen Reduction Performance of Platinum Ternary Alloy‐Oxide in Solid‐Polymer‐Electrolyte Fuel Cells

The effect of base metal oxide (nonnoble metal oxide) in a Pt‐Cr‐Cu alloy catalyst is investigated for the oxygen reduction reaction in a solid‐polymer‐electrolyte fuel cell. The cathode mass activities at 0.9 V for Pt, Pt‐Cr alloy, Pt‐Cr‐Cu alloy, and a mixture of Pt‐Cr‐Cu alloy with base metal oxide are compared. The enhancement factor is largest (about 6 times) for the mixture of Pt‐Cr‐Cu alloy with base metal oxide, compared to Pt‐Cr and Pt‐Cr‐Cu alloys (about 2 times). The higher electrocatalytic activity of this material may be due to the combined effects of the Pt‐Cr‐Cu alloy and the base metal oxide. The physical and electrochemical characterizations are carried out using various techniques like x‐ray diffraction, transmission electron microscopy, cyclic voltammetry, polarization, and ac impedance.