Oxophilic-metallic cooperative interfaces for efficient carbon dioxide electroreduction

Efficient electrochemical carbon dioxide (CO₂) reduction is fundamentally hindered by the difficulty of activating the chemically inert CO₂ molecule while maintaining rapid product release. For silver-based catalysts, this challenge originates from the limited stabilization of oxygen-containing intermediates during the initial proton-coupled electron-transfer process. Here, we report a rare-earth-enabled interfacial polarization strategy by incorporating oxophilic lanthanum into Ag nanoparticles supported on Ketjenblack carbon. The resulting LaAg/KB catalyst achieves a carbon monoxide (CO) Faradaic efficiency exceeding 95% over a wide operating window and maintains stable operation for 70 h. Combined experimental and theoretical investigations demonstrate that spontaneous charge redistribution between La and Ag generates polarized AgLa interfacial sites, which selectively stabilize oxygen-containing intermediates through localized electrostatic interactions. This interfacial polarization substantially lowers the energy barrier for key intermediate (*COOH) formation, thereby accelerating the rate-limiting CO₂ activation step. Meanwhile, the electronically reconstructed Ag sites preserve favorable CO desorption kinetics, enabling efficient product release. Beyond conventional electronic-structure engineering, this work identifies interfacial polarization as an effective mechanism for molecular activation and intermediate regulation, offering a new design principle for advanced electrocatalysts toward carbon-neutral energy conversion.