Defect and Interface Engineering for Aqueous Electrocatalytic CO2 Reduction

Electrocatalytic CO2 reduction (ECR) with rationally designed electrocatalysts is a promising strategy to reduce CO2 emission and produce value-added products. Reactive sites of heterogeneous catalysts usually lie on the surface and subsurface, which allow improvement of the catalytic property by engineering the surface atoms. Defects of an electrocatalyst, such as dopants, atom vacancies, and grain boundaries, have potential to enable unconventional adsorption behaviors and chemical activities of reactants on the catalyst surface, and selectively enhance the stability of specific intermediates and corresponding ECR pathways. Moreover, the interface between two different electrocatalyst components can also stabilize active surface catalytic sites and enable their synergetic effects. In this review, we summarize how surface defects and interface can be rationally designed and functioned in ECR catalysts, and how these atomic-level controlling approaches help to promote efficiency and selectivity. The challenges and prospects are also discussed to suggest the future designs of ECR catalysts.