Charge‐Asymmetric Dual‐Cu Sites in a Metal‐Organic Framework Direct CO ₂ Electroreduction to Ethanol

Abstract

ABSTRACT The selective electrochemical CO 2 reduction reaction (CO 2 RR) to ethanol is constrained by copper's intrinsic kinetic preference for the ethylene‐forming *CO→*COH pathway over the ethanol‐selective *CO→*CHO route. Conventional solutions break this preference by introducing extrinsic chemical heterogeneity. Herein, we report an approach to generating electronic asymmetry in a homometallic system. The in‐situ construction of a chemically bonded interface between a binuclear Cu‐MOF and copper foil (cf) induces electron transfer, transforming symmetric Cu dimers into cooperative, charge‐asymmetric dual sites. These sites function as a kinetic gate, raising the barrier for *CO→*COH while lowering it for *CO→*CHO to direct selectivity toward ethanol, as confirmed by in‐situ spectroscopy and DFT. The findings indicate that interfacial electron redistribution can provide a straightforward means to encode functional asymmetry in homometallic electrocatalysts and to modulate multistep reaction pathways.