Enhancing the selectivity of CO2-to-HCOOH conversion by constructing tensile-strained Cu catalyst

Heterogeneous interface engineering endows catalyst with the possibility to enhance the activity and tune the selectivity of electrochemical CO2 reduction reaction (CO2RR) by induced surface strain and interfacial charges transfer. Herein, a novel In2O3/Cu heterojunction catalyst with 3D succulents-like morphology significantly enhance the selectivity and activity for electrochemical CO2-to-HCOOH conversion as compared to the In2O3 and Cu counterparts, achieving a maximum faraday efficiency (FE) of 87.5 % at −1.1 V vs RHE with corresponding formate partial current density of −70 mA cm−2 at −1.4 V vs RHE. The combined DFT calculation and experimental studies revealed that electrons transfer from interfacial In to Cu via O bridge preserves the metallic state of Cu, which facilitates the capture and activation of CO2 molecules. Furthermore, the surface tensile strain together with interfacial electronic interaction lowers the energy barrier for the formation of *HCOO intermediate, thus boosting the selectivity for HCOOH production. This work demonstrates a feasible strategy for advanced catalyst design by implanted heterogeneous interfaces to manipulate the lattice strain and electronic coupling.