Solid-Diffusion Synthesis of Single-Atom Catalysts Directly from Bulk Metal for Efficient CO2 Reduction

Electroreduction of CO2 into value-added products is an effective approach to remit the environmental and energy issues. However, the development of an effective, accessible, and simple method for mass production of electrocatalyst is challenging. Herein, we demonstrate the solid-state diffusion between the N-doped carbon phase and bulk Ni metal can be utilized to synthesize hierarchical, self-supported, and atomistic catalyst. Strikingly, this hierarchical catalyst is programmable and scalable to meet the industrial demand and can be directly used as a binder-free electrode toward the CO2 electroreduction, delivering a state-of-the-art current density of 48.66 mA cm−2 at −1.0 V versus reversible hydrogen electrode (RHE) and high faradic efficiency of 97% to CO. The selectivity can be retained over 90% in a wide range of working potential of −0.7 to −1.2 V versus RHE. This solid-state diffusion strategy presents great potential to produce hierarchical and atomistic catalysts at industrial levels.