Catalytic Ethylene Oligomerization over Ni-Loaded X-AlSBA-15 (X = Gd, Y, La, and Sm) Catalysts

This study evaluated the performance of Ni-X-AlSBA-15 (X = Y, Sm, Gd, and La) catalysts in the ethylene oligomerization processes. The effects of Y, Sm, Gd, and La promoters on the ethylene oligomerization process were examined. The Ni-X-AlSBA-15 (X = Y, Sm, Gd, and La) catalysts demonstrated a considerably enhanced catalytic activity and selectivity compared with that of Ni-AlSBA-15. In particular, the Ni-Gd-AlSBA-15 catalyst achieved the highest conversion of ethylene to butene (50.0 wt.%) after 12 h of time on stream. These enhancements were attributed to the improved dispersion of active sites, the presence of oxygen vacancies, and the optimized densities of the acid and Ni sites, which collectively enhanced the rate of adsorption of ethylene molecules. An increase in the selectivity of butylene (≥ 80%) confirmed that the gadolinium as a promoter had a positive effect on the catalytic activity. Overall, the Gd promoter, coupled with the remarkable benefits of AlSBA-15 in Ni-based catalysts, is promising for butene generation through ethylene oligomerization.