Simultaneous Capture of CO2 Boosting Its Electroreduction in the Micropores of a Metal-organic Framework.

Abstract

Integration of CO2 capture capability from flue gas and electrochemical CO2 reduction reaction (eCO2RR) active sites into a catalyst is a promising cost-effective strategy for carbon neutrality, but is of great difficulty. Herein, combining the mixed gas breakthrough experiments and eCO2RR tests, we showed that a Ag12 cluster-based metal-organic framework (1-NH2, aka Ag12bpy-NH2), simultaneously possessing CO2 capture sites as "CO2 relays" and eCO2RR active sites, can not only utilize its micropores to efficiently capture CO2 from simulated flue gas (CO2:N2 = 15:85, at 298 K), but also catalyze eCO2RR of the adsorbed CO2 into CO with an ultra-high CO2 conversion of 60%. More importantly, its eCO2RR performance (a Faradaic efficiency (CO) of 96% with a commercial current density of 120 mA cm-2 at a very low cell voltage of -2.3 V for 300 hours and the full-cell energy conversion efficiency of 56%) under simulated flue gas atmosphere is close to that under 100% CO2 atmosphere, and higher than those of all reported catalysts at higher potential under 100% CO2 atmosphere. This work bridges the gap between CO2 enrichment/capture and eCO2RR.