HYDROISOMERIZATION OF n-HEXADECANE ON ZEOLITE CATALYSTS

摘要

Bifunctional platinum catalysts containing MCM-22, ZSM-5, SAPO-11 and H-Beta were tested for their hydroisomerization of n-hexadecane(n-C_(16)), and their catalytic activities and selectivity were compared. Pt/MCM-22 and Pt/ZSM-5 catalysts showed lower isomerization selectivity due to their strong acidity, while Pt/SAPO-11 and Pt/H-Beta catalysts showed higher selectivity. Through the analysis of the product distribution, the hydroisomerization mechanism on Pt/SAPO-11 was discussed. It was showed that the isomerization of long chain n-paraffins on medium pore zeolite took place at the external surface and pore mouth of the zeolite. The hydroisomerization selectivity was greatly influenced by the catalyst acidity. Weak and mild acids were favorable to isomerization.