Lewis Acid Site-Promoted Single-Atomic Cu Catalyzes Electrochemical CO2 Methanation

Developing an efficient catalyst for the electrocatalytic CO₂ reduction reaction (CO₂RR) is highly desired because of environmental and energy issues. Herein, we report a single-atomic-site Cu catalyst supported by a Lewis acid for electrocatalytic CO₂ reduction to CH₄. Theoretical calculations suggested that Lewis acid sites in metal oxides (e.g., Al₂O₃, Cr₂O₃) can regulate the electronic structure of Cu atoms by optimizing intermediate absorption to promote CO₂ methanation. Based on these theoretical results, ultrathin porous Al₂O₃ with enriched Lewis acid sites was explored as an anchor for Cu single atoms; this modification achieved a faradaic efficiency (FE) of 62% at -1.2 V (vs RHE) with a corresponding current density of 153.0 mA cm^-2 for CH₄ formation. This work demonstrates an effective strategy for tailoring the electronic structure of Cu single atoms for the highly efficient reduction of CO₂ into CH₄.