Highly Strained Interfaces and Phase Separation for Boosting Electrochemical Methanol Oxidation and Hydrogen Evolution

Constructing multimetallic alloy heterostructures with the desired interface and phase separation is a promising method to optimize the electrochemical properties of noble metal nanomaterials. Nevertheless, tailoring the elemental distribution and lattice structures of such multimetallic nanomaterials still poses major difficulties. In this study, Cu-PtNi nanowires coupling PtNi with PtNiCu active sites are fabricated by seeded synthesis on a Cu template. Owing to the oxophilic nature of PtNi sites and the anti-CO poisoning capability of PtNiCu facets, the as-synthesized Cu-PtNi nanowires exhibit enhanced methanol oxidation reaction (MOR) performance (7.73 A mg_Pt^-1), outperforming those of PtNiCu alloy, PtNi alloy, and commercial Pt/C catalysts. Theoretical calculations in conjunction with <i>operando</i> infrared reflection absorption spectroscopy demonstrate that the lattice-compressed Pt₃Ni (111)-Pt₃NiCu (100) interface stands out as a highly efficient active site, which promotes OH intermediate adsorption and simultaneously weakens CO intermediate adsorption during the MOR. In addition, at 10 mA cm^-2, Cu-PtNi nanowires also exhibit an impressively reduced overpotential of 35.2 mV for the hydrogen evolution reaction (HER) under alkaline conditions. This work offers a strategy to boost the electrocatalytic performance of multimetallic nanomaterials.