Enrichment Strategies for Efficient CO2 Electroreduction in Acidic Electrolytes.

Electrochemical CO2 reduction reaction (CO2RR) has been recognized as an appealing route to remarkably accelerate the carbon‐neutral cycle and reduce carbon emissions. Notwithstanding great catalytic activity that has been acquired in neutral and alkaline conditions, the carbonates generated from the inevitable reaction of the input CO2 with the hydroxide severely lower carbon utilization and energy efficiency. By contrast, CO2RR in an acidic condition can effectively circumvent the carbonate issues; however, the activity and selectivity of CO2RR in acidic electrolytes will be decreased significantly due to the competing hydrogen evolution reaction (HER). Enriching the CO2 and the key intermediates around the catalyst surface can promote the reaction rate and enhance the product selectivity, providing a promising way to boost the performance of CO2RR. In this review, the catalytic mechanism and key technique challenges of CO2RR are first introduced. Then, the critical progress of enrichment strategies for promoting the CO2RR in the acidic electrolyte is summarized with three aspects: catalyst design, electrolyte regulation, and electrolyzer optimization. Finally, some insights and perspectives for further development of enrichment strategies in acidic CO2RR are expounded. [ABSTRACT FROM AUTHOR]