Synthesis, Physicochemical Properties and Catalytic Performance of a Modified ZSM-5 Molecular Sieve

Abstract

A modified ZSM-5 molecular sieve was prepared by the combination of recrystallization and carbon template methods. The samples were characterized by X-ray diffraction, N2 adsorption-desorption, NH3-TPD, TEM and SEM. The results show that the modified ZSM-5 molecular sieve has double pore distribution. The diameters of the two kinds of channels are 0.51~0.56 nm and 1.4~1.6 nm, respectively. In addition, the modified HZSM-5 (H-type ZSM-5) sample mainly has moderate strength of acid sites. Finally, the alkylation of benzene with 1-dodecene olefin was used to evaluate the catalytic performance of the as-synthesized modified ZSM-5 on macromolecules. The conversions of 1-dodecene on the modified ZSM-5, ZSM-5 prepared by conventional process and aluminum-containing SBA-15 mesoporous molecular sieve are 96%, 39% and 83%, respectively. And the selectivities of long chain alkyl benzene on those are 97%, 68% and 91%, respectively. The catalytic properties of the modified ZSM-5 on macromolecules are superior to those of ZSM-5 prepared by conventional process and aluminum-containing SBA-15 mesoporous molecular sieve.