Facile synthesis of ternary PtPdCu alloy hexapods as highly efficient electrocatalysts for methanol oxidation

Abstract

Developing an efficient Pt-based multimetallic electrocatalyst with well-defined shapes for methanol oxidation reaction (MOR) is critical, however, it still remains challenging. Here we report a one-pot approach for the synthesis of ternary PtPdCu alloy hexapods with different compositions. Their MOR activities increased in the sequence Pt₂PdCu₄ < Pt₃PdCu₄ < Pt₅PdCu₅, and were substantially higher than that of commercial Pt/C. Specifically, the Pt₅PdCu₅ hexapods exhibited the highest mass (0.97 mA μg_Pt⁻¹) and specific (7.39 mA cm⁻²) activities towards MOR, and were 5.4 and 19.4 times higher than those of commercial Pt/C (0.18 mA μg_Pt⁻¹ and 0.38 mA cm⁻²), respectively. This enhancement could be probably attributed to the bifunctional mechanism and ligand effect through the addition of Cu and Pd as well as the unique dendritic structure. The better tolerance for CO poisoning also endowed the PtPdCu hexapods with superior durability relative to commercial Pt/C.