Ag Atom Induces\nMicrostrain Environment around Cd\nSites to Construct Diatomic Sites for Almost 100% CO<sub>2</sub>‑to-CO\nElectroreduction

Deeply understanding how local microstrain environment\naround diatomic\nsites influences their electronic state and adsorption is crucial\nfor improving electrochemical CO<sub>2</sub> reduction (eCO<sub>2</sub>R) reaction; however, precise engineering of the atomic microstrain\nenvironment is challenging. Herein, we fabricate Ag-CdTMT electrocatalysts\nwith AgN<sub>2</sub>S<sub>2</sub>–CdN<sub>2</sub>S<sub>2</sub> diatomic sites by anchoring Ag to the nodes of CdTMT (TMT = 2,4,6-trimercaptotriazine\nanion) coordination polymers. The Ag-CdTMT catalysts achieve approximately\n100% Faradaic efficiency for CO reduction with an industrial level\ncurrent density (∼200 mA cm<sup>–2</sup> in H-cell).\nThe embedded Ag atoms induce the formation of Ag–Cd diatomic\nsites with local microstrain, stretching Cd–N/S bonds, and\nreinforcing electron localization at Cd sites. The microstrain engineering\nand adjacent Ag atoms synergistically reduced Cd 4d–C 2p antibonding\norbital occupancy for intensifying *COOH adsorption as the rate-determining\nstep. This study provides novel insights into customizing the electronic\nstructure of diatomic sites through strain engineering.