Synergistic electronic-spatial design in hollow multi-shell FeCo@MoS2 nanoreactors for efficient electrochemical CO2-to-CH4 conversion

Electronic-interface-confinement synergy enables full CO 2 -to-CH 4 conversion. • Achieves 65.4% CH 4 FE and 100 h stability with non-Cu catalyst, a new benchmark. • Nanoconfinement steers CO 2 -to-CH 4 by stabilizing intermediates and lowering HCOOH→HCO→H 2 CO* barrier. • S-vacancies and FeCo/Mo-edge electronic synergy boost activity and selectivity. • Topological transformation constructs tunable multi-shelled confinement nanoreactors. The electrochemical CO 2 reduction reaction (CO 2 RR) still faces critical challenges in achieving rapid product conversion and precise selectivity control due to kinetic limitations and thermodynamic competition. To overcome these limitations, this study develops a hierarchical hollow multi-shell FeCo@MoS 2 catalyst that integrates electronic modulation with nanoconfinement, thereby achieving kinetic enhancement and directional steering of methane production. This enhanced performance stems from two factors: sulfur vacancy-rich monolayer MoS 2 that enhances carrier mobility, and the synergistic effect of strong Mo-edge/FeCo coupling combined with nanoscale confinement for site stabilization. The optimized FeCo@MoS 2 -p30 (with pore size ≈30 nm) delivers a high methane Faradaic efficiency of 65.4% with 80 mA cm −2 at −1.0 V vs. RHE and exceptional operational stability for over 100 h. The computational results reveal that FeCo@MoS 2 -p30 promotes efficient methane production by steering the reaction pathway through a sequence of key intermediates. The nanoconfinement effect selectively stabilizes the adsorption of HCOO*, HCOOH*, HCO*, and H 2 CO* (favoring the HCOO* pathway over COOH), thereby redirecting the selectivity toward CH 4 . This is achieved by substantially reducing the energy barrier for the rate-determining HCOOH* → HCO* hydrogenation steps. Download: Download high-res image (167KB) Download: Download full-size image