Engineering d-orbital of copper single-atom sites toward industrial-level electrocatalytic methanation

Copper (Cu)-based single-atom catalysts (SACs) enable electrocatalytic CO2 reduction into methane (CH4) fuel for thermal power plant decarbonization, yet conventional Cu SACs face industrial deployment barriers like instability and sluggish kinetics caused by d − p orbital coupling. Herein, we develop a Cu–Ti1O3 catalyst with localized Cu single-atom sites by oxygen vacancy (Ov)-involved orbital engineering, achieving industrial-level CH4 production. Theoretical and in-situ studies reveal the intensification of the d − d coupling at Cu sites triggered by [Cu−Ov − Ti] motifs, which enhances d-π* polar interactions upon *CO2 and accelerates C − O bond cleavage in *OCH3 intermediate. As a result, Cu–Ti1O3 achieves a competitive performance, i.e., the highest Faradaic efficiency of 76% and a peak partial current density of 670 mA cm−2 toward CH4 (corresponding turnover frequency = 24,930 h−1), ~3.5-fold promotion over conventional Cu SACs. Furthermore, it demonstrates high durability (>1,230 hours) at an industrial-level current density, exceeding the longevity of conventional Cu SACs by over 20 times. Our findings highlight the prospect of d-orbital engineering in enabling industrial-level electrocatalytic methanation, offering promising implications for decarbonizing traditional power plants. The instability and sluggish kinetics of conventional Cu single-atom catalysts inhibit their industrial deployment in CO2-to-methane conversion. Here, the authors propose a d-orbital engineering strategy to construct localized Cu sites, achieving stable industrial-level electrocatalytic methanation.