Synthesis of ultrathin wrinkle-free PdCu alloy nanosheets for modulating d-band electrons for efficient methanol oxidation

Abstract

The synthesis of ultrathin noble-metal-based alloy nanosheets with few-atomic-layer thickness remains a great challenge although they have attracted remarkable attention. Herein, ultrathin wrinkle-free Pd₄Cu₁ nanosheets with lateral size of 33.8 nm and thickness of 2.71 nm were successfully prepared using n-butylamine as a bifunctional agent. The ingenious structure possesses the highest electrochemically active surface area among the reported PdCu nanostructures. The quantum confinement and entrapment effects of the Pd₄Cu₁ nanosheets render the modulation of d-band electrons and weaken the adsorption of poisoning species, thus enhancing the performance towards methanol oxidation. The mass activity of the ultrathin wrinkle-free Pd₄Cu₁ nanosheets was 6.7-times and 4.8-times higher than that of commercial Pd black and Pt black, respectively. This study highlights the important role of designing ultrathin alloy nanosheets towards enhancing electrocatalytic performance.