Dual-functional basic microenvironment in Sr-doped La2CuO4 for selective CO2 electroreduction to CH4 via cooperatively promoting CO2 adsorption and H2O dissociation

Electrocatalytic carbon dioxide reduction reaction (CO 2 RR) to produce value-added methane (CH 4 ) represents a promising approach to achieve carbon recycling and addressing global energy challenges. However, this reaction is currently hindered by limitations in catalytic selectivity and efficiency. Herein, we present a strategy involving strontium (Sr) doping at the A-site of La 2 CuO 4 perovskite (denoted as Sr x -LCO) to regulate surface basicity, thereby significantly enhancing catalytic performance for CO 2 RR toward CH 4 formation. The optimized Sr 0.04 -LCO catalyst achieves a Faradaic efficiency of 68.8% for CH 4 at −1.1 V (vs. RHE), which is significantly higher than that of undoped La 2 CuO 4 (44.1%) and at the top level among public reports. The results indicate that successful Sr doping to the La-site promotes electron transfer through the La−O−Cu linkage, generating a local alkaline microenvironment around the Sr−O sites. This microenvironment enhances CO 2 chemisorption and provides abundant reactive protons (*H). Theoretical calculations further confirm that the localized alkaline region reduces the activation energy barriers for the rate-determining steps (*CO 2 → *COOH and *CO → *COH) and suppresses the competing hydrogen evolution reaction (HER), thereby selectively steering the reaction pathway toward CH 4 formation. This study elucidates the mechanistic role of surface microenvironment modulation in enhancing CO 2 reduction reaction (CO 2 RR) selectivity for lanthanide perovskite, offering new insights for the rational design of high-performance electrocatalysts.