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.