Electrocatalytic CO2 reduction in acidic medium

Electrocatalytic carbon dioxide (CO2) reduction has been consid-ered as a promising pathway to achieve carbon neutrality. In alkaline or near-neutral medium, considerable catalytic activity has been reached. However, the inevitable reaction of CO2 molecules with hydroxide ions forms carbonates, leading to low energy efficiency and carbon utilization. CO2 electrolysis in acidic medium provides a viable alternative to reduce carbonate production and achieve low energy consumption for CO2 conversion due to the high carbon utilization and low overpotential for anodic oxygen evolution reac-tion. Herein, we discuss the progress for efficient electroreduction of CO2 in acidic medium, wherein theory-guided discovery of cations' actions, rational design of electrode/catalysts, and local pH effect together accelerate the achievement of acidic CO2 elec-troreduction. An outlook is provided about the future development of efficient acidic CO2 electrolysis, which concerns the catalyst/elec-trode design and catalytic microenvironment optimization for boosting the selectivity of C-C coupling.

Automated summary

Electrocatalytic reduction of CO2 has been considered a promising pathway for carbon neutrality. Although considerable catalytic activity has been achieved in alkaline or near-neutral mediums, the formation of carbonates from the reaction between CO2 molecules and hydroxide ions leads to low energy efficiency and carbon utilization. Electrolysis of CO2 in acidic medium provides a viable alternative with high carbon utilization and low overpotential for anodic oxygen evolution reaction. This article discusses the progress in efficient CO2 electroreduction in acidic medium, including the discovery of cations' actions, rational design of electrode/catalysts, and local pH effect. The future development of efficient acidic CO2 electrolysis, focusing on catalyst/electrode design and catalytic microenvironment optimization to enhance the selectivity of C-C coupling, is also discussed.