Structurally ordered Pt–Zn/C series nanoparticles as efficient anode catalysts for formic acid electrooxidation

Abstract

Controlling the size, composition, and structure of bimetallic nanoparticles is of particular interest in the field of electrocatalysts for fuel cells. In the present work, structurally ordered nanoparticles with intermetallic phases of Pt₃Zn and PtZn have been successfully synthesized via an impregnation reduction method, followed by post heat-treatment. The Pt₃Zn and PtZn ordered intermetallic nanoparticles are well dispersed on a carbon support with ultrasmall mean particle sizes of ∼5 nm and ∼3 nm in diameter, respectively, which are credited to the evaporation of the zinc element at high temperature. Meanwhile, these catalysts are less susceptible to CO poisoning relative to Pt/C and exhibited enhanced catalytic activity and stability toward formic acid electrooxidation. The mass activities of the as-prepared catalysts were approximately 2 to 3 times that of commercial Pt at 0.5 V (vs. RHE). This facile synthetic strategy is scalable for mass production of catalytic materials.