Synthesis and Catalytic Performance of Mesoporous Material by Two-step Crystallization

Abstract

A mesoporous material was synthesized by using the precursor of MCM-22 zeolite through a two-step synthesis route,and characterized by XRD,N2 physical adsorption-desorption,TEM,27 Al MAS NMR,IR spectra of pyridine adsorbed methods and so on.It was found that the synthesized sample was not a mixture of microporous zeolite and mesoporous material but a new mesoporous molecular sieve with strong acid sites and good thermal stability.The acid catalytic activity for macromolecules was evaluated and compared with conventional mesoporous material MCM-41 through the cracking reaction of cumene and alkylation reaction of benzene with 1-dodecen.The results show that the conversions of cumene cracking at 350℃ over the new mesoporous material and MCM-41 are 68.98% and 48.80%,respectively.For the alkylation reaction of benzene with 1-dodecen at 210℃,the conversions of 1-dodecen over the new mesoporous materials and MCM-41 are around 95.20% and 86.89%,respectively.The selectivities of linear alkylbenzene over the new mesoporous materials and MCM-41 are around 88.11% and 90.06%,respectively.The results show that the catalytic property of the new mesoporous materials for macromolecules is superior to that of MCM-41.