Atomic-level Ag─Sn Coordination Engineering in Laser-Synthesized Cu₆Sn₅ Alloys for Energy-Efficient Electroreduction CO₂ to Formate.

Abstract

Cu-Sn alloy (Cu_xSn_y) has emerged as a promising category of catalysts for the electrochemical CO₂ reduction reaction (CO₂RR) to produce formate. Introducing heteroatoms to regulate the electronic structure of the active site is a common method to further improve the catalytic performance. However, owing to the existence of multiple active sites on the alloy surface, realizing the fine-tuned coordination environment in Cu_xSn_y remains a persistent challenge through heteroatom doping. Here precise Ag─Sn and Ag─Cu coordinated Cu₆Sn₅ alloys are developed by a laser-induced nonequilibrium synthesis strategy. Compared to Cu₆Sn₅ and Ag─Cu coordinated Cu₆Sn₅ (Ag─Cu'₆Sn₅), Ag─Sn coordinated Cu₆Sn₅ catalyst (Ag─Cu₆Sn'₅) achieves a superior formate conversion performance in CO₂RR by optimizing the electronic structure at the d-band center, which enhances the concentration of CO₂ on the catalyst surface and reduces the activation barrier of rate-determining step, i.e., the electron transfer step of adsorbed CO₂ to generate the intermediate ^*CO₂ ^- as validated by electrokinetic, in situ spectroscopic and theoretical investigations. Furthermore, integrating the Ag─Cu₆Sn'₅ catalyst with glycerol oxidation instead of conventional oxygen evolution lowers energy consumption by 68.57% while effectively increasing formate production rate. This work provides a laser-driven strategy for precise coordination modulation in alloy catalysts, advancing energy-efficient CO₂ conversion systems.