From Precatalysts to Real Active Phases: Dynamic Reconstruction of CO2 Reduction Electrocatalysts

Abstract

Electrochemical CO₂ reduction reaction (CO₂RR) provides a promising way to convert CO₂ into fuels and value-added chemicals using renewable electricity. However, many CO₂RR catalysts do not keep their original structures under reaction conditions. They often undergo dynamic reconstruction, including changes in the oxidation state, coordination environment, phase composition, morphology, defect density, and interfacial structure. These reconstructed states usually serve as the real active phases and strongly affect activity, selectivity, and stability. This review summarizes recent progress in understanding catalyst reconstruction during CO₂RR. We first clarify the concept of precatalyst reconstruction and distinguish initial structures from real active phases. We then discuss the intrinsic and external factors that drive reconstruction. We further examine representative reconstructed catalysts, including Cu-based, non-Cu metal, and MOF- or coordination-compound-derived systems. We also highlight in situ characterization and simulation methods. Finally, we discuss key challenges and future opportunities for catalyst reconstruction.