Highly CO tolerant PtRu/PtNi/C catalyst for polymer electrolyte membrane fuel cell

Abstract

Galvanic displacement and annealing treatment were used to construct a PtRu/PtNi/C catalyst with PtRu on the surface and PtNi in the core. PtNi alloy was formed during high-temperature reduction, and the surface Ni in the PtNi alloy was subsequently replaced by Ru in RuCl₃ solution. The H₂ annealing treatment at 300 °C increased the crystallinity by surface PtRu alloy formation. The prepared PtRu/PtNi/C catalyst demonstrated higher CO electro-oxidation activity than PtNi/C, PtNi–Ru/C and PtRu/C catalysts. The enhanced CO tolerance is ascribed to the synergistic effect between the PtRu surface and the PtNi core, which induces oxygen containing species produced on surface Ru sites at low potentials, weakened adsorption of CO on metal sites, and high PtRu utilization.