Mercaptosilane-assisted synthesis of highly dispersed and stable Pt nanoparticles on HL zeolites for enhancing hydroisomerization of n-hexane

The synergistic effect between metal and acid sites has been considered to be of great importance to n-alkane hydroisomerization catalyzed by bifunctional catalysts. Herein, we report a facile mercaptosilane-assisted in situ synthesis approach to achieve stable and highly dispersed small Pt nanoparticles supported on HL zeolite catalysts (Pt/HL-SH) for n-hexane hydroisomerization. In comparison with the catalysts (Pt/HL-C) synthesized by a traditional ion-exchange method, the Pt/HL-SH catalysts show both high activity and excellent catalytic stability and also no obvious sintering of Pt nanoparticles is observed during the reaction due to the fact that the Pt/HL-SH catalysts possess both higher dispersion of Pt particles within the HL nanocrystals and more mesopores produced by mercaptosilane. Moreover, the regeneration stability of n-hexane hydroisomerization over Pt/HL-SH catalysts was also examined by five continuous cycles, demonstrating excellent regeneration properties. Thus, the mercaptosilane-assisted in situ synthesis approach is a promising way to prepare bifunctional catalysts for enhancing their catalytic performance in n-alkane hydroisomerization.

Automated summary

The synergistic effect between metal and acid sites is important for the catalytic hydroisomerization of n-alkane. The Pt/HL-SH catalysts, prepared by a mercaptosilane-assisted in situ synthesis approach, show high activity, excellent catalytic stability, and no sintering of Pt nanoparticles during the reaction. The approach of mercaptosilane-assisted in situ synthesis is promising for enhancing the catalytic performance in n-alkane hydroisomerization.