Additives‐Modified Electrodeposition for Synthesis of Hydrophobic Cu/Cu2O with Ag Single Atoms to Drive CO2 Electroreduction

Abstract

Copper‐based electrocatalysts are recognized as crucial catalysts for CO2 electroreduction into multi‐carbon products. However, achieving copper‐based electrocatalysts with adjustable valences via one‐step facile synthesis remains a challenge. In this study, Cu/Cu2O heterostructure is constructed by adjusting the anion species of the Cu ions‐containing electrolyte during electrodeposition synthesis. Then, Cu/Cu2O with tuned nanoarchitectures ranging from dendrites to polyhedrons is achieved by introducing transition metal ions as additives, leading to an adjustable interfacial microenvironment for CO2/H2O adsorption on the Cu/Cu2O electrodes. Additionally, the polyhedral Cu/Cu2O catalysts are used as templates for depositing Ag single atoms (AgSA), which are known as synergistic active sites for promoting *CO to *COH toward C2+ products. The prepared AgSA‐Cu/Cu2O catalyst is evaluated in a flow cell and exhibited a FEC2+ of 90.2% and a partial current density (jc2+) of 426.6 mA cm−2 for CO2 electroreduction. As revealed by in situ Raman spectra and density functional theory calculations, the introduction of Ag single atoms slows down the reduction of Cu+ during CO2 electroreduction, especially at a high current density. This work provides a promising paradigm for diverse control of the compositions and hydrophobicity of Cu‐based catalysts for selective CO2 electroreduction to C2+ products.