Stable and Active p-Block Metal-Doped Cu ₂ O Catalysts for the Electrochemical Reduction of CO ₂ into CO

High Resolution Image Download MS PowerPoint Slide Incorporating a secondary metal into a host material is an effective strategy to modulate its electronic structure and enhance electrocatalytic performance. Low-concentration doping, which minimizes perturbations to the host lattice and surface, enables precise material engineering while reducing synthesis complexity and costs. However, achieving stable low-concentration doping is challenging due to potential dopant leaching under dynamic electrochemical conditions. Here, we demonstrate that dilute incorporation of p-block elements (≤2.50 wt %) into Cu 2 O significantly enhances its CO 2 -to-CO conversion efficiency and operational stability. The lowest effective doping concentrations were 0.37 wt % for tin and 2.03 wt % for indium, both exhibiting negligible leaching. Remarkably, these dopants decrease the work function of Cu 2 O even at such low concentrations, contributing to improved catalytic performance. Moreover, both tin and indium suppress the reduction of Cu 2 O to metallic copper, maintaining high CO conversion efficiency over extended operation. Our findings demonstrate that low-concentration doping with p-block metals can effectively tune the electronic structure and enhance the electrocatalytic performance of copper-based catalysts.