Durable Cathodes and Electrolyzers for the Efficient Aqueous Electrochemical Reduction of CO2.

The world emits over 14 gigatons of CO2 in excess of what can be remediated by natural processes annually, contributing to rising atmospheric CO2 levels and increasing global temperatures. The electrochemical reduction of CO2 (CO2 RR) to value-added chemicals and fuels has been proposed as a method for reusing these excess anthropogenic emissions. While state-of-the-art CO2 RR systems exhibit high current densities and faradaic efficiencies, research on long-term electrode durability, necessary for this technology to be implemented commercially, is lacking. Previous reviews have focused mainly on the CO2 electrolyzer performance without considering durability. In this Review, the need for research into high-performing and durable CO2 RR systems is stressed by summarizing the state-of-the-art with respect to durability. Various failure modes observed are also reported and a protocol for standard durability testing of CO2 RR systems is proposed.