Additives-Modified Electrodeposition for Synthesis of Hydrophobic Cu/CuO with Ag Single Atoms to Drive CO Electroreduction.

Copper-based electrocatalysts are recognized as crucial catalysts for CO 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/CuO heterostructure is constructed by adjusting the anion species of the Cu ions-containing electrolyte during electrodeposition synthesis. Then, Cu/CuO with tuned nanoarchitectures ranging from dendrites to polyhedrons is achieved by introducing transition metal ions as additives, leading to an adjustable interfacial microenvironment for CO/HO adsorption on the Cu/CuO electrodes. Additionally, the polyhedral Cu/CuO catalysts are used as templates for depositing Ag single atoms (Ag), which are known as synergistic active sites for promoting CO to COH toward C products. The prepared Ag-Cu/CuO catalyst is evaluated in a flow cell and exhibited a FE of 90.2% and a partial current density (jc) of 426.6 mA cm for CO 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 CO 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 CO electroreduction to C products.