Compressive strain-mediated bond length tailoring in CuO reveals the bridge to efficient electrocatalytic CO2-to-ethylene conversion

Abstract

Modulation of the electronic microenvironment of copper (Cu) sites during electrochemical carbon dioxide reduction (ECR) is essential for controlling the strength of intermediate adsorption and improving electron transfer. However, precisely regulating the electronic microenvironment around Cu through adjustment of the Cu–O bond length remains a significant challenge. Here, we report a strategy that achieves fine-tuned control over the electronic microenvironment around the active center through lattice compression. Experimental results show that the introduction of Cd alters the Cu–O bond length and the electronic microenvironment around Cu and significantly enhances the adsorption of *CO and *COOH intermediates. Density functional theory calculations reveal that the optimal degree of lattice compression modulates the binding energy of *COOH intermediates, and enhances the d-band center, improving CO₂ adsorption. Furthermore, we verified that the structure–activity relationship between bond length change and catalytic activity is consistent with a volcanic-type trend. Remarkably, the O–CuCd-4 catalysts exhibited impressive CO₂-to-C₂H₄ conversion performance (FE_C2H4 ≈ 60% and EE_C2H4 ≈ 30%) with good stability that matches or exceeds that of most reported Cu-based oxides. This study provides a rational pathway for designing catalysts with precisely modifiable electronic microenvironments, resulting in enhanced CO₂ conversion activity and long-term stability.