(58a) Hierarchical Gallosilicate MFI Catalyst Development for Natural Gas Conversion

Direct conversion of lower-alkanes (CH₄/C₂H₄) into liquid aromatic hydrocarbons in the absence of oxygen in a single step dehydroaromatization (DHA) is consider as an economical and environmentally friendly approach for natural gas utilization. The metal-zeolite catalysts are the most adequate catalysts for lower-alkanes DHA, however, the rapid catalyst deactivation caused by coke deposition on the external and internal surfaces covering active sites and blocking of the micropores of the support, is a major challenge to commercial application of this technology.

In order to improve the metal-zeolite DHA catalyst’s anti-coke ability, various approaches have been attempted, including incorporation of active metal into the zeolite tetrahedral silica structural frameworks, use of hierarchical or mesoporous structure zeolite support, doping of a promoter to catalyst. In this study, we developed a hierarchical gallosilicate ZSM-5 with Pt promoter catalyst (PtGaMZ-5) for lower-alkanes DHA. Compare with traditional impregnation method prepared mesopore ZSM-5 supported PtGa-MZ-5 catalyst or micropore Pt promoted gallosilicate ZSM-5 (PtGaZSM-5) catalyst, with the in-structure activity metal and mesoporous structure help, the PtGaMZ-5 high activity in C₂H₆ DHA, with the highest C₂H₆ conversion and aromatics selectivity.