Preparation of low-platinum-content platinum–nickel, platinum–cobalt binary alloy and platinum–nickel–cobalt ternary alloy catalysts for oxygen reduction reaction in polymer electrolyte fuel cells

Abstract

A series of low-platinum-content platinum–nickel (Pt–Ni), platinum–cobalt (Pt–Co) binary alloys and platinum–nickel–cobalt (Pt–Ni–Co) ternary alloys electrocatalysts were successfully prepared by a three-step process based on electrodeposition technique and studied as electrocatalysts for oxygen reduction reaction (ORR) in polymer-electrolyte fuel cells. Kinetics of ORR was studied in 0.5 M H2SO4 solution on the Pt–Ni, Pt–Co and Pt–Ni–Co alloys catalysts using rotating disk electrode technique. Both the series of Pt–Ni, Pt–Co binary alloys and the Pt–Ni–Co ternary alloys catalysts exhibited an obvious enhancement of ORR activity in comparison with pure Pt. The significant promotion of ORR activities of Pt–Ni and Pt–Co binary alloys was attributed to the enhancement of the first electron-transfer step, whereas, Pt–Ni–Co ternary alloys presented a more complicated mechanism during the electrocatalysis process but a much more efficient ORR activities than the binary alloys.