Highly efficient electrocatalysis dechlorination of Dichloromethane over Single-Atom Cu/Co3O4-β spinel nanofibers

Electrochemical selective dechlorination of dichloromethane (DCM) to chloromethane is a promising and sustainable strategy of resources. However, the current lack of high-performance electrocatalysts and complicated dechlorination mechanisms pose significant challenges. In this study, we report a series of Cu single-atom catalysts (SACs) supported on Co3O4-β spinel with a tube-in-tube nanofiber structure, denoted as Cux SACs/Co3O4-β, where x represents the theoretical Cu loading (0.26 wt%, 0.30 wt% and 0.50 wt%). These catalysts effectively dechlorinate DCM, producing high-value hydrocarbons like chloromethane and methane. Notably, Cu0.30 SACs/Co3O4-β exhibited a high chloromethane production rate (2931 μmol g−1h−1) and selectivity (76%) at −2.98 V vs (Ag/AgCl/Me4NCl) due to the synergy of cobaltosic oxide (Co3O4) spinel and Cu single atom. X-ray photoelectron spectroscopy and electron paramagnetic resonance experiments confirmed the presence of additional surface oxygen vacancies in Cu0.30 SACs/Co3O4-β, which improved the electrocatalysis performance for DCM dechlorination. Furthermore, a concerted dechlorination mechanism was suggested based on the transfer coefficient α. This research paves the way for the development of novel spinel electrocatalysts and the advancement of dechlorination reactions.