Modulating surface microenvironment based on Ag-adorned CuO flower-liked nanospheres for strengthening C-‍C coupling during CO2RR

Modulating the surface microenvironment is crucial in strengthening C C coupling, leading to increasing selectivity in the production of multi-carbon (C 2+ ) products during CO 2 electroreduction. Herein, we have concentrated on investigating how to control the effect of surface distribution of active components of a series of Ag-decorated CuO , denoted as xAg/yCuO. These catalysts with similar chemical elements and morphology are designed, but they exhibit different selectivity in the CO 2 electroreduction process. As a result, the Ag particles in 3Ag/CuO aggregates, while the Ag in 2Ag/2CuO and Ag/3CuO is uniformly distributed on the flower-like CuO nanosphere . Besides, 3Ag/CuO has the highest Faraday efficiency (FE) of CO with a value of 30.9 % at 0.8 V vs. RHE, demonstrating rich-Ag catalysts are beneficial to produce CO. 2Ag/2CuO shows excellent FE C2H4 of 51.4 % at -1.2 V vs. RHE due to the highly dispersed distribution of Ag on the flower-like CuO and higher vacancy O. Ag/3CuO exhibits higher FE H2 compared to other catalysts across a wide potential range, and its minimal impedance is attributed to its exceptional performance in the hydrogen evolution reaction . The proposed reaction pathway for the most effective catalysts 2Ag/2CuO, as determined by in-situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), involves the following steps: CO 2 →*CO 2 − → *COOH → *CO→ *CHO→ *OCHCHO→ *OCHCH 2 → C 2 H 4 . These findings demonstrate that controlling the surface structure can influence the local environment to enhance the efficiency of CO 2 electroreduction.