Self‐Healing Indium Sulfide Catalyst for Efficient and Robust Electrocatalytic CO2 Conversion

Abstract The reduction–reconstruction of the catalyst under negative bias has been identified as a significant rationale underlying the performance degradation of the electrocatalytic CO 2 reduction reaction (CO 2 RR). Screening catalysts with stable phases and robust crystal structures appears to be a feasible approach to counteract the reduction corrosion. In this work, with the guidance of computational predictions, a tetragonal phase In 2 S 3 electrocatalyst is designed through a self‐healing strategy for the conversion of CO 2 to formate. Remarkably, In 2 S 3 exhibits superior stability for over 200 h at a current density of ∼210 mA cm −2 , with a persistent formate faradaic efficiency of ∼97%. A series of in situ spectroscopic measurements confirm that In 2 S 3 maintains the structural and valence state integrity throughout the reaction. Combined with density functional theory calculations, the performance enhancement mechanism and self‐healing principle of In 2 S 3 are clearly elucidated. This work provides a novel perspective for the design of highly efficient and stable CO 2 RR electrocatalysts.