Unraveling catalytic properties by yttrium promotion on mesoporous SBA-16 supported nickel catalysts towards CO2 methanation
Résumé
The ordered mesoporous silica SBA-16 with high specific surface area and pore volume was synthesized and used to prepare Ni/SBA-16 catalysts promoted with yttrium. These promoted catalysts were tested in CO 2 methana-tion reaction and characterized by N 2 sorption, small-angle/wide-angle XRD, TEM, XPS, H 2-TPR, CO 2-TPD, and TGA/DSC-MS. The results revealed that Ni/Y/SBA-16 catalysts performed better catalytic performance in CO 2 methanation compared to the non-promoted Ni/SBA-16 catalyst. The best catalytic activity was found for the catalyst promoted with 10 wt% Y. The improved performance of such catalysts was attributed to the increase of reducibility of nickel species, the increase in surface oxygen species, and the abundance of moderate basic sites caused by Y promotion. Furthermore, the CO 2 reaction rate and turnover frequency of CO 2 were well correlated with the number of moderate basic sites. Finally, all the tested catalysts are highly stable during the 8 h time-on-stream catalytic test.