Implanting CuNi Alloy into NiVOx for H₂ Evolution with Ultralow Overpotential and Highly Selective Formate Production

Electrochemical upgrading of biomass waste (such as glycerol)-assisted water electrolysis for the production of valuable formate and high-purity hydrogen offers a promising route to develop sustainable and clean sources of energy. Herein, using a simple two-step electrodeposition method to implant CuNi alloy in VOx-doped Ni (NiVOx), we construct a competent, stable, and bifunctional heterogeneous catalyst (CuNi–NiVOx) toward hydrogen evolution reaction (HER) and glycerol electrooxidation reaction (GER). The CuNi–NiVOx electrode presents excellent HER activity with an ultralow overpotential of 8 mV in 1.0 M KOH to deliver a current density of 10 mA cm–2 and high GER activity for selective formate production with high Faradaic efficiency (FE). Moreover, the hybrid electrolytic cell formed by the bifunctional CuNi–NiVOx catalyst was able to reach a current density of 10 mA cm–2 with an ultralow voltage (1.308 V). X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations confirm the existence of electron transfer between the O sites and metal sites and between heterogeneous interfaces, thus optimizing the hydrogen adsorption ability (0.02 eV). This work may provide ideas for the engineering of heterogeneous dual-function electrocatalysts for energy-saving hydrogen production and simultaneous highly selective production of formate.