Coupling electrochemical CO2 conversion with CO2 capture

Electrochemical CO2 conversion into fuels or chemicals and CO2 capture from point or dilute sources are two important processes to address the gigaton challenges in reducing greenhouse gas emissions. Both CO2 capture and electrochemical CO2 conversion are energy intensive, and synergistic coupling between the two processes can improve the energy efficiency of the system and reduce the cost of the reduced products, via eliminating the CO2 transport and storage or eliminating the capture media regeneration and molecular CO2 release. We consider three different levels to couple electrochemical CO2 reduction with CO2 capture: independent (Type-I), subsequent (Type-II) and fully integrated (Type-III) capture and conversion processes. We focus on Type-II and Type-III configurations and illustrate potential coupling routes of different capture media, which include amine-based solutions and direct carbamate reduction, redox active carriers, aqueous carbonate and bicarbonate solutions, ionic liquids CO2 capture and conversion mediated by covalent organic frameworks. The practical implementation of CO2 electrocatalysis is premised on the availability of captured CO2-a consideration that is often overlooked. This Perspective presents several concepts for integrating CO2 capture with electrochemical CO2 conversion for the enhancement of overall efficiency.

Automated summary

Electrochemical CO2 conversion into fuels or chemicals and CO2 capture from point or dilute sources are two important processes to address the gigaton challenges in reducing greenhouse gas emissions. Both processes are energy intensive, but synergistic coupling between them can improve energy efficiency and reduce costs, by eliminating the need for CO2 transport and storage or capture media regeneration.