Synthesis of hierarchical Mo/H-IM-5 catalysts by using mesoporous material as the silica source and its application in methane non-oxidative aromatization

A novel hierarchical porous IM-5 (IM-5-K) was synthesized by using mesoporous silica KIT-6 as the silica sources. The physical properties and acidities of the samples were characterized by XRD, SEM, TEM, BET and NH₃-TPD. Moreover, Mo-modified catalyst, Mo-IM-5-K was prepared for non-oxidative aromatization of methane. Compared with Mo-IM-5-C, the Mo-IM-5-K catalyst showed higher conversion of methane and yields of aromatics. In addition, Mo-IM-5-K exhibited better stability than Mo-IM-5-C. Different activities and stabilities of the catalysts may be due to their different structure properties and acidities. The existence of secondary mesoporous systems may influence the location and state of the active Mo species, simultaneously lead to easier access to the active sites for reactants and better diffusion of aromatic products, thus improvs the activities of the catalysts.