Regulating the\nElectrochemical Microenvironment of\nNi(OH)<sub>2</sub> by Cr Doping for Highly Efficient Methanol Electrooxidation

Nickel-based catalysts demonstrate promising potential\nin integrated\nhydrogen production via methanol electro-oxidation (MOR). However,\nthe MOR involves multiple hydroxide ions (OH<sup>–</sup>) and\nmultielectron synergistic catalytic processes in alkaline electrolytes.\nThe low OH<sup>–</sup> capture capability of Ni-based catalysts\nleads to a reduced energy conversion efficiency. Furthermore, the\ncompetitive adsorption of H<sub>2</sub>O and CH<sub>3</sub>OH molecules\non the catalyst surface blocks active sites, resulting in a decreased\nselectivity for formate. To address these challenges, effectively\nmanipulating the electrochemical microenvironment has emerged as a\nviable strategy. In this study, we successfully achieved selective\nelectrooxidation of methanol to formate on Ni(OH)<sub>2</sub> by incorporating\na hard Lewis acid heteroatom (Cr) to finely tune the electrochemical\ninterface microenvironment. Experimental and theoretical investigations\nreveal that incorporating ordered Cr atoms into Ni(OH)<sub>2</sub> can establish a hydrophobic interface, suppressing the blockage\nof active sites and promoting the enrichment of OH<sup>–</sup> at the electrified interface. By leveraging the enhanced localized\nalkalinity and hydrophobic microenvironment at the modified electrified\ninterface, high-value formate can be effectively synthesized with\nnearly 100% selectivity over a wide potential range. Furthermore,\nthe catalysts display robust electrocatalytic capabilities, delivering\nremarkable performance with a high current density of 50 mA cm<sup>–2</sup> at a working potential of 1.45 V vs RHE.