| Abstract |
Mesoporous xNi-yMg-Al2O3 catalysts containing x wt.% Ni and y wt.% Mg were prepared by combined evaporation induced self-assembly (EISA) and one-pot techniques, and tested in the CO2 methanation reaction. The effects of Mg and Ni loadings on the catalysts properties and performances were systematically studied. Higher Mg contents enhanced methanation performances due to more favourable metallic interactions between the Ni, Mg and Al species. In addition, higher Ni contents led to better CO2 conversions and selectivity to CH4 by enhancing methane formation that involves H2 dissociation on Ni0 sites. A systematic comparative study based on the type of support was properly assessed. In this way, the mesoporous 5Ni-Al2O3 catalyst obtained by the EISA technique was compared to catalysts containing 5 wt.% Ni supported on USY zeolite and SBA-15. Moreover, the most promising mesoporous material (15Ni-7Mg-Al2O3, leading to 65% of CO2 conversion and 95% of CH4 selectivity at 350 ºC, 1435 ml·min-1·gcatalyst-1) was compared to a commercial hydrogenation catalyst (25Ni/?-Al2O3) under the same reaction conditions. In all cases, one-pot materials revealed the most promising performances. |
