Catalytic CO₂ Conversion Using Metal Catalysts Supported on Porous Structured Materials

The catalytic hydrogenation of CO₂ into value-added products is a promising strategy for mitigating greenhouse gas emissions. This work investigated Ni-supported MCM-41 catalysts prepared by wet impregnation with 7, 10, and 15 wt.% Ni. The materials were characterized by XRD, EDX, TGA, and N₂ physisorption. MCM-41 exhibited a high specific surface area (1475 m² g⁻¹) and an ordered hexagonal mesoporous structure. XRD confirmed the presence of the NiO phase, with crystallite sizes ranging from 6.86 to 11.20 nm. Catalytic tests performed at 400 °C after H₂ reduction at 500 °C showed CO₂ conversions of 37%, 92%, and 78%, and CH₄ selectivity of 51%, 87%, and 83% for 7Ni/MCM-41, 10Ni/MCM-41, and 15Ni/MCM-41, respectively. The superior performance of 10Ni/MCM-41 indicates that optimizing Ni loading, rather than minimizing crystallite size alone, is essential for maximizing catalytic efficiency.