Phosphorus-Enhanced Oxygen Reduction Activity and Stability of Commercial Pt/C

Tuesday, 3 October 2017
Prince George's Exhibit Hall D/E (Gaylord National Resort and Convention Center)
B. A. Lu (Xiamen University), N. Tian (Department of Chemistry, Xiamen University), Z. Y. Zhou (Xiamen University), and S. G. Sun (Department of Chemistry, Xiamen University)
In fuel cell technologies, the sluggish kinetics of oxygen reduction reaction (ORR) on the cathode is the main obstacle, and it is thus urgent to develop high-performance catalysts. Recently, the role of surface Pt-OH in the ORR has drawn much attention and the highly active ORR catalysts reported recently show much less surface Pt-OH coverage than pure Pt does. Previously, lots of work have focused on tuning the surface electronic structure of platinum-based catalysts, controlling its interaction with reactants, and thus affects the efficiency.

In this work, we report that Phosphorus adsorption of moderate coverage could substantially enhance the activity and stability of commercial carbon supported Pt electrocatalyst towards oxygen reduction reaction. Compared to pure Pt/C, P-decorated commercial Pt/C exhibited weakened oxygen affinity on the surface, and 8-times higher specific activity and 7-times higher mass activity at 0.9 V. Furthermore, compared to commercial Pt/C, we observed that the stability of phosphorus-decorating commercial Pt/C can be enhanced dramatically. The mass activity loss of phosphorus-decorating commercial Pt/C is only 10%, much smaller than that of Pt/C (51%) after 10,000 potential cycles between 0.6-1.0 V. This study may provide a strategic design of Pt-based efficient ORR catalysts for fuel cells.