Synergistic Ni-Co Dual Single Atoms on Oxygen-Deficient CeO₂ Nanorods for Efficient and Coke-Resistant Photothermal Dry Reforming of Methane.

Abstract

Solar-driven photothermal catalytic dry reforming of methane (DRM) offers a sustainable route to convert two greenhouse gases into syngas, yet its practical application is limited by unsatisfactory performance and deactivation. Here, we report an efficient and stable photothermal DRM catalyst based on synergistic Ni-Co dual single-atom catalysts anchored on CeO₂ nanorods. Under 12.17 W cm^-2 illumination, the optimized Ni₈Co₄/CeO₂ delivers high H₂ and CO production rates of 3383.01 and 4703.36 mmol g^-1 h^-1, respectively, with an H₂ to CO ratio of 0.72 that exceeds the thermodynamic equilibrium limit. Moreover, a record-high light-to-fuel efficiency of 40.9% is obtained with excellent long-term stability. Mechanistic studies reveal a cooperative dual single-atom effect. Ni single atoms act as the primary sites for CH₄ activation, while Co single atoms stabilize abundant oxygen vacancies in the CeO₂ support, promoting CO₂ activation to form O* and OH* species. These oxygen fluxes intercept CH₃* via the oxygen-assisted CH₃O* pathway, reducing carbon deposition and the side reaction. These findings present a general strategy that employs dual single-atom engineering to develop efficient, coke-resistant catalysts for solar-driven highly endothermic reactions.