Galvanic replacement-mediated synthesis of Pd–Cu alloy nanospheres as electrocatalysts for formic acid oxidation

Abstract

Rational synthesis of bimetallic electrocatalysts with the special geometric structure for direct formic acid fuel cells remains yet challenging. Herein, a facile synthetic strategy is presented to prepare the bimetallic Pd–Cu alloy nanospheres (Pd–Cu ANSs) catalysts based on the galvanic replacement and high-temperature reconstruction. The formation mechanism of Pd–Cu ANSs is studied thoroughly from comprehensive characterizations and control experiments. The optimized Pd–Cu ANSs with unique nanosphere structure as well as regulated electronic structure provide excellent electrocatalytic performance for formic acid oxidation reaction (FAOR) with a specific activity of 6.11 mA cm-2Pd and mass activity of 1569.48 mA mg-1Pd, which are 2.7 times and 3.5 times as high as these of the Pd/C catalyst. This synthetic method outlined here could provide a new pathway for noble metal-based alloy nanomaterials for diverse applications.