Superior catalytic performance of micro-mesoporous Beta-SBA-15 composite with a high indexed isomerization factor in hydroisomerization of n-heptane

A composite material Beta-SBA-15 (BS) comprising zeolite Beta units and SBA-15-like mesoporous structure was hydrothermally synthesized and served as catalyst support for the hydroisomerization of n-heptane. Materials were characterized by a variety of techniques. Characterization results revealed that Beta-SBA-15 composite has a two-dimensional hexagonal mesoporous channel with a pore size of 6.4 nm and a high concentration of moderate-strength acid sites. Evaluation results showed that Pt/HBS exhibited a relatively high n-heptane conversion (75.57%) with a good selectivity to isoheptanes (90.04%), resulting in the highest isoheptanes yield (68.04%) among all samples. The micro-mesoporous composite structure with moderate surface acidity enhanced diffusion of large isomerized intermediates as well as inhibiting the occurrence of cracking side reactions, achieving a high isoheptanes yield. Experimental data demonstrates that the indexed isomerization factor (IIF) as a performance descriptor can accurately predict the isomerization performance of catalysts.