Tailoring metal-support interaction by engineering Ni/CeO2 interfacial contact for boosting low-temperature CO2 methanation

CO 2 methanation is an important route for carbon emission mitigation and renewable energy storage. However, insufficient CO 2 activation and inefficient hydrogenation of surface intermediates at low temperatures remain major challenges. In this work, Ni/CeO 2 catalysts with distinct metal-support interaction degrees were constructed by regulating the interfacial contact of Ni-Ce, aiming to enhance the low-temperature methanation performance. The results suggest that Ni/CeO 2 with strengthened Ni-CeO 2 interfacial interaction exhibits more oxygen-vacancy-related defect sites, improved reducibility, and favorable Ni dispersion. These interrelated features collectively facilitate CO 2 adsorption/activation and intermediate conversion, thereby contributing to the enhanced low-temperature methanation performance. Specifically, the CO 2 conversion reached ∼80% at 250 °C. In situ Raman spectroscopy suggested the dynamic evolution of oxygen-vacancy-related defect sites during the reaction, while in situ DRIFTS suggested that CO 2 methanation may proceed through both the formate-mediated pathway and the CO* pathway. These findings suggest that tailoring the Ni-Ce interfacial interaction, together with the associated changes in oxygen vacancy related defects, reducibility, and Ni dispersion, may provide an effective approach to improving the low-temperature CO 2 methanation performance of Ni-based catalysts.