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

Integration of CO2 capture capability from simulated flue gas and electrochemical CO2 reduction reaction (eCO(2)RR) 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 an Ag-12 cluster-based metal-organic framework (1-NH2, aka Ag(12)bpy-NH2), simultaneously possessing CO2 capture sites as CO2 relays and eCO(2)RR active sites, can not only utilize its micropores to efficiently capture CO2 from simulated flue gas (CO2 : N-2=15 : 85, at 298 K), but also catalyze eCO(2)RR of the adsorbed CO2 into CO with an ultra-high CO2 conversion of 60 %. More importantly, its eCO(2)RR 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 potentials under 100 % CO2 atmosphere. This work bridges the gap between CO2 enrichment/capture and eCO(2)RR.

Automated summary

This study demonstrates the integration of CO2 capture capability and electrochemical CO2 reduction reaction (eCO2RR) active sites using a silver-based metal-organic framework. The catalyst showed efficient CO2 capture from simulated flue gas and high conversion of adsorbed CO2 into CO during eCO2RR. The study has bridged the gap between CO2 enrichment/capture and eCO2RR.