Mitigating carbonate formation in CO2 electrolysis

Abstract

Electrochemical CO2 reduction reaction (CO2RR) that could utilise massive CO2 from industrial flue gas and the atmosphere provides a promising method to convert CO2 to value-added fuels and feedstocks powered by renewable electricity. Although significant progress has been made recently, carbonate formation in alkaline and neutral electrolytes reduces the longevity of the device and induces extra cost in CO2 regeneration, thus limiting the application of CO2RR. In this review, we summarise recent efforts in overcoming this issue and thus achieving high single pass CO2 utilization: CO2RR in acid media, tandem CO2RR with CORR, and electrolysis of CO2 capture media. We discuss detailedly the advantages and challenges of each system by comparing their performances with alkaline/neutral CO2RR. This in return supports our perspective on the further improvement in the technical and economic viability of CO2RR process.

Keywords

• Electrochemical CO2 reduction
• Carbonate formation
• Acidic electrolyte
• Tandem electrolysis
• Electrolysis of capture media