In-situ encapsulation synthesis of Ni-Ce/SBA-15 by EISA for promoting CO2 methanation

CO 2 methanation is a critical process for converting CO 2 greenhouse gas into clean methane fuel, which holds significant strategic importance for environmental sustainability and energy sectors. Thermodynamic limitations demand low-temperature catalysts with enhanced low-temperature activity. This study employs solvent evaporation-induced self-assembly (EISA) to in-situ encapsulate Ni and Ce within SBA-15 molecular sieves. The approach significantly enhances low-temperature reactivity, achieving 67.5% CO 2 conversion and nearly 100% CH 4 selectivity at 300 °C, outperforming among Ni-based catalysts with silica carriers. Textural and electronic characterizations reveal that confinement effects of SBA-15 and electronic promotion of Ce synergistically strengthen the low temperature activity in methanation. This results in smaller Ni nanoparticles and an electron-rich Ni state, optimizing catalytic performance. Mechanistic analysis suggests that the Ce-modified Ni catalyst favors the formate pathway over the CO pathway, which supports the high methane selectivity and low carbon monoxide selectivity observed in this study.