Boosting CO2 Electroreduction to CH4 via Tuning Neighboring Single Copper Sites

Electroreduction of CO2 into valuable products such as hydrocarbons is an efficient strategy for CO2 conversion and energy storage, while it remains highly challenging to understand and well control the capability of tuning electrocatalysts for different hydrocarbon products. Herein, we report a Cu single-atom catalyst dispersed on nitrogen-doped carbon by an N-coordination strategy. The presence of nitrogen enabled well dispersion and attachment of atomic Cu species on the nitrogen-doped carbon frameworks with Cu−Nx configurations. The Cu doping concentrations and Cu−Nx configurations were well-tuned by the pyrolysis temperature. At a high Cu concentration of 4.9%mol, the distance between neighboring Cu−Nx species was close enough to enable the C−C coupling and produce C2H4. In contrast, at Cu concentrations lower than 2.4%mol, the distance between Cu−Nx species was large so that the electrocatalyst favored to form CH4 as C1 products. Density functional theory calculations further confirmed the capabilit...