Boosting CO2 Electroreduction to CH4 via Tuning Neighboring Single-Copper Sites

We report single-atom Cu catalysts dispersed on nitrogen-doped carbon by a nitrogen-coordination strategy. The presence of nitrogen enabled good dispersion and attachment of atomic Cu species on the nitrogen-doped carbon frameworks with Cu–N x configurations. The Cu doping concentrations and Cu–N x configurations were well-tuned by the pyrolysis temperature. At a high Cu concentration of 4.9% mol, the distance between neighboring Cu–N x species was close enough to enable C–C coupling and produce C 2 H 4 . In contrast, at Cu concentrations lower than 2.4% mol, the distance between Cu–N x species was large so that the electrocatalyst favored the formation of CH 4 as C 1 products. Density functional theory calculations further confirmed the capability of producing C 2 H 4 by two CO intermediates binding on two adjacent Cu–N 2 sites, while the isolated Cu–N 4, the neighboring Cu–N 4, and the isolated Cu–N 2 sites led to formation of CH 4 . Our work demonstrates a facile approach of tuning active Cu sites for CO 2 electroreduction to different hydrocarbons.