Synthesis Strategies for the Optimization of Ni–Ce–Al Catalysts in the Conversion of CO ₂ to Methanol

The increase in carbon dioxide (CO2) emissions has driven the search for sustainable alternatives, such as catalytic hydrogenation for methanol production. This work investigates how different synthesis methods affect the physicochemical properties and catalytic performance of Ni-Ce-Al-based materials applied to CO2 hydrogenation. Three catalysts, with fixed contents of Ni (20% w/w) and CeO2 (12% w/w), were prepared by direct impregnation (Ni-ID), sequential impregnation (Ni-IS), and sol-gel (Ni-SG). Techniques such as XRD, SEM-EDS, N2 physisorption, FTIR, H2-TPR, CO chemisorption, CO2-TPD, and TPSR were employed to correlate the structure, metal dispersion, redox properties, and basic sites with catalytic activity. The Ni-SG catalyst exhibited a higher specific surface area, stronger metal-support interaction, and greater methanol productivity, outperforming the materials obtained by impregnation. The results demonstrate that the sol-gel route promotes the homogeneous incorporation of phases and the formation of more accessible active sites, contributing to a more selective and efficient CO2 conversion. The study highlights the role of synthesis methods as a key strategy in the development of sustainable and high-efficiency catalysts.