Rare-Earth Y–O Skeleton-Mediated Stabilization of Cu2+ for Efficient CO2 Electroreduction to CH4

Copper-based catalysts show considerable promise in the electrochemical CO 2 reduction reaction (CO 2 RR) for the production of hydrocarbons and oxygenates, particularly methane (CH 4 ), which is a highly reduced product. The high-valent state of copper (Cu) exerts a positive influence on the formation pathway of CH 4 , but the reduction potential will lead to a decrease in the valence state during CO 2 RR. In this study, a highly crystalline and structurally well-defined Y 2 Cu 2 O 5 catalyst is constructed to stabilize Cu 2+ with the orderly alternating Y─O skeleton layer, owing to the strong bonding interaction. The Y 2 Cu 2 O 5 exhibits a remarkable enhancement in CH 4 selectivity compared to CuO (up to 9.59-folds), achieving a selectivity of 61.3% at 300 mA cm −2 and 58.4% at 400 mA cm −2 , together with good stability. In situ attenuated total reflectance Fourier transform infrared spectra (ATR-FTIR) and density functional theory (DFT) calculations reveal that the presence of the Y─O skeleton layer in Y 2 Cu 2 O 5 significantly enhances the adsorption of *CO intermediate, and accelerates its hydrogenation process, facilitating the conversion of CO 2 to CH 4 . This work highlights Y─O skeleton-mediated stabilization of Cu 2+ for efficient electroreduction of CO 2 to CH 4 , providing valuable insights into the design of efficient electrocatalysts for CO 2 conversion.