Transition Metal Ion Doping on ZIF‐8 Enhances the Electrochemical CO2 Reduction Reaction

Abstract The electrochemical reduction of CO 2 to diverse value‐added chemicals is a unique, environmentally friendly approach for curbing greenhouse gas emissions while addressing sluggish catalytic activity and low Faradaic efficiency (FE) of electrocatalysts. Here, zeolite‐imidazolate‐frameworks‐8 (ZIF‐8) containing various transition metal ions—Ni, Fe, and Cu—at varying concentrations upon doping are fabricated for the electrocatalytic CO 2 reduction reaction (CO 2 RR) to carbon monoxide (CO) without further processing. Atom coordination environments and theoretical electrocatalytic performance are scrutinized via X‐ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations. Upon optimized Cu doping on ZIF‐8, Cu 0.5 Zn 0.5 /ZIF‐8 achieves a high partial current density of 11.57 mA cm –2 and maximum FE for CO of 88.5% at –1.0 V (versus RHE) with a stable catalytic activity over 6 h. Furthermore, the electron‐rich sp 2 C atom facilitates COOH* promotion after Cu doping of ZIF‐8, leading to a local effect between the zinc–nitrogen (Zn–N 4 ) and copper–nitrogen (Cu–N 4 ) moieties. Additionally, the advanced CO 2 RR pathway is illustrated from various perspectives, including the pre‐H‐covered state under the CO 2 RR. The findings expand the pool of efficient metal–organic framework (MOF)‐based CO 2 RR catalysts, deeming them viable alternatives to conventional catalysts.