Electrocatalytic CO2 reduction to C2+ products on CeO2-modified CuO catalyst

Abstract

Electrocatalytic CO₂ reduction reaction (CO₂RR) for producing valuable multi-carbon (C₂₊) chemicals is considered very promising, yet the rational design of catalysts and the regulation of reaction pathways remain difficult. Here, via introducing CeO₂ on CuO catalyst, the Faradic efficiency of C₂₊ products, including C₂H₄ and ethanol, is obviously increased from 64% for CuO to as high as 87% for CeO₂/CuO catalyst, along with a high partial current density of 0.52 A cm⁻², and the C₂H₄ : C₂H₅OH ratio is obviously decreased. After introducing CeO₂, CO₂/CO adsorption is greatly enhanced as the electronic structure of Cu sites is regulated by CeO₂, and H₂O dissociation is promoted owing to the interfacial synergistic effect between Cu and CeO₂. More importantly, the C–C coupling process changes from an endothermic process to a spontaneous *CO or *CHO dimerization process, which is critical for the enhanced selectivity of C₂₊ products. This work highlights that CeO₂ promotes C–C coupling in CO₂RR toward C₂₊ products on Cu-based catalysts by regulating adsorption properties.