Synergistic Effects of Doping and Strain in Bismuth Catalysts for CO2 Electroreduction

Abstract Doping is a recognized method for enhancing catalytic performance. The introduction of strains is a common consequence of doping, although it is often overlooked. Differentiating the impact of doping and strain on catalytic performance poses a significant challenge. In this study, Cu‐doped Bi catalysts with substantial tensile strain are synthesized. The synergistic effects of doping and strain in bismuth result in a remarkable CO 2 RR performance. Under optimized conditions, Cu 1/6 ‐Bi demonstrates exceptional formate Faradaic efficiency (>95%) and maintains over 90% across a wide potential window of 900 mV. Furthermore, it delivers an industrial‐relevant partial current density of −317 mA cm −2 at −1.2 V RHE in a flow cell, while maintaining its selectivity. Additionally, it exhibits exceptional long‐term stability, surpassing 120 h at −200 mA cm −2 . Through experimental and theoretical mechanistic investigations, it has been determined that the introduction of tensile strain facilitates the adsorption of *CO 2 , thereby enhancing the reaction kinetics. Moreover, the presence of Cu dopants and tensile strain further diminishes the energy barrier for the formation of *OCHO intermediate. This study not only offers valuable insights for the development of effective catalysts for CO 2 RR through doping, but also establishes correlations between doping, lattice strains, and catalytic properties of bismuth catalysts.