Large π-conjugated indium-based metal-organic frameworks for high-performance electrochemical conversion of CO2

The active site engineering of electrocatalysts, as one of the most economical and technological approaches, is a promising strategy to enhance the intrinsic activity and selectivity towards electrochemical CO2 reduction reaction. Herein, an indium-based porphyrin framework (In-TCPP) with a well-defined structure, highly dispersed catalytic center, and good stability was constructed for efficient CO2-to-formate conversion. In-TCPP could achieve a high Faraday efficiency for formate (90%) and a cathodic energy efficiency of 63.8% in flow cells. In situ attenuated total reflectance Fourier transform infrared spectroscopy and density functional theory calculation confirm that the crucial intermediate is *COOH species which contributes to the formation of formate. This work is expected to provide novel insights into the precise design of active sites for high-performance electrocatalysts towards electrochemical CO2 reduction reaction.