Highly Selective Hydrodeoxygenation of Dibenzofuran into Bicyclohexane over Hierarchical Pt/ZSM-5 Catalysts
Xiaoxue Li, Xiaopo Niu, Shuaikang Zhu, Shuang Xu, Zheyuan Wang, Xiangwen Zhang, Qingfa Wang
Abstract
Fabricating zeolite-supported catalysts with excellent catalytic performance for hydroconversion of bio-oils into high-quality fuels is still a great challenge. Herein, hierarchical ZSM-5 zeolites were successfully synthesized with 3-[(trimethoxysilyl) propyl] octadecyldimethylammonium chloride as a mesoporous template. The hierarchical ZSM-5 supported Pt catalysts (Pt/HZ-x) were used to enhance the hydrodeoxygenation of dibenzofuran into bicyclohexane, and the influence of acidity distribution on the reaction pathways was investigated by tailoring the Si/Al molar ratios (50, 75, and 100). For all catalysts, cycloalkanes were produced via the partial hydrogenation of the aromatic rings to generate tetrahydrodibenzofuran, followed by the cleavage of C—O bond. The optimal bicyclohexane selectivity (86.8%) was obtained on Pt/HZ-75 catalyst due to the good synergistic effect between metal dispersion and acid distribution. This catalyst also showed excellent stability because of its strong metal–support interactions. Even after reused five times, the catalytic activity was almost unchanged compared with the fresh one. Furthermore, the possible reaction pathways for conversion of dibenzofuran into bicyclohexane over Pt/HZ-x catalysts were developed.