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 Cu2O significantly enhances its CO2-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 Cu2O even at such low concentrations, contributing to improved catalytic performance. Moreover, both tin and indium suppress the reduction of Cu2O 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.
Gandionco et al. (Wed,) studied this question.