Efficient Electrochemical CO2 Conversion to CO via Cu-Doped Induced Lattice Compression in Ag Nanosheets

Abstract

Lattice strain is widely recognized as an effective strategy for tuning transition metal catalytic activity, yet its direct impact on electrochemical CO₂ reduction (ECO₂RR) remains not fully understood. In this work, a strategy of Cu-doped Ag is employed to construct a series of AgCu nanosheet structures (NS) with varying lattice compression rates (from −1.90% to −2.75%). Density Functional Theory (DFT) calculations, along with in situ infrared spectroscopic analysis, demonstrate that Cu incorporation efficiently modulates the electronic structure of Ag, promoting enhanced charge transfer. Especially, the changed lattice compression rates can alter the charge density at adsorption sites, thereby ameliorating the surface coverage of CO and adsorption energy of the reaction intermediates (^*COOH and ^*CO). As a result, the AgCu_5% catalyst exhibits a maximum Faradaic efficiency (FE) of 95.5% for CO production in an H-cell and 98% in a flow cell at −0.8 V_RHE, respectively. Simultaneously, the AgCu_5% catalyst achieves FE_CO of above 86% in the ultrawide current range of 33–215 mA cm⁻². The work affords an effective way to use a strain compression strategy to improve the CO₂ reduction performance.