摘要
In this study, a catalyst system featuring multi-scale heterogeneous junctions was successfully constructed via a controlled aqueous-phase chemical reduction strategy. The structure consists of Ni(OH)₂ nanoparticles supported on a TiO₂ substrate, with only 1 wt% of oxygen-deficient CoOx sub-nanoclusters embedded on the surface. Within this design, surface cobalt atoms and oxygen vacancies (Ov)s synergistically modulate the electronic structure of nickel, thereby altering its hydrogen dissociation capacity and intermediate adsorption behavior. Simultaneously, the oxygen vacancies serve as effective traps for Oads species during the CO₂ methanation reaction, facilitating active site regeneration. Through spatial coupling and interfacial electronic synergy between the heterogeneous components, the overall apparent activation energy was significantly reduced to 45.4 kJ mol⁻¹ . As a result, the CH₄ production rate was enhanced by approximately 40 % (from 4657.7 to 6516.4 μmol g⁻¹) compared to the CoOx-free control, without compromising methane selectivity. These findings demonstrate that surface modification with trace amounts of CoOx clusters can effectively induce interfacial electronic reconfiguration and cooperative catalytic behavior, offering a concrete strategy for designing efficient catalysts for CO₂ thermal conversion.
•CoOx clusters introduce extra active sites on TiO₂-supported Ni(OH)₂ for CO₂ methanation.•Co–Ni–vacancy interfaces tune adsorption energy and enhance CO hydrogenation.•CH₄ yield improves by ∼39.9 %, revealing the synergy of Ni, Co, and oxygen vacancies.