Atomic-level engineering of two-dimensional electrocatalysts for CO2 reduction

Carbon dioxide (CO2) from the excessive consumption of fossil fuels has exhibited a huge threat to the planet's ecosystem. Electrocatalytic CO2 reduction into value-added chemicals has been regarded as a promising strategy in CO2 utilization and needs the development of advanced electrocatalysts for lowering the activation energy and enhancing selectivity in CO2 reduction. Two-dimensional (2D) materials, benefiting from their unique geometrical structures, have been extensively studied in the electrocatalytic CO2 reduction reaction (CO2RR). In this review, we systematically overview atomic-level engineering strategies in 2D electrocatalysts for the CO2RR, including thickness control, elemental doping, vacancy engineering, heterostructure construction, and single-atom loading. Meanwhile, we analyze the relationship between structures and activity in electrocatalysis, and present the future challenges and opportunities in the electrocatalytic CO2RR, and we hope that this review will offer helpful guidance for developing electrocatalysts for the CO2RR.