Comparison of Pt/zeolite catalysts for n-hexadecane hydroisomerization

Bifunctional platinum (0.5 wt.%) catalysts containing ZSM-5, ZSM-22, SAPO-11, Al-MCM-41, H-Y and H-P were tested for the hydroisomerization of n-hexadecane and their catalytic activities were compared. The Pt/ZSM-5, Pt/ZSM-22 and Pt/H-beta catalysts showed higher hydrocracking activity due to their strong acid sites,while the Pt/SAPO-11, Pt/Al-MCM-41 and Pt/H-Y catalysts with moderate acid strength showed better isomerization selectivity. Especially the Pt/Al-MCM-41 catalyst, where Al-MCM-41 was prepared by post-synthetic metal implantation method from siliceous MCM-41, showed the highest isomerization selectivity as well as the highest yield of multibranched isohexadecanes, presumably not only due to its moderately weak acidity and mesoscale pores but also due to higher metal dispersion. This result indicates that the Pt/Al-MCM-41 catalyst can be a promising candidate for good dewaxing catalysts. (C) 2000 Elsevier Science B.V. All rights reserved.