关键词: HZSM-5催化剂, 临氢芳构化；Zn 、K改性；正庚烷

Abstract:

HZSM-5 zeolite was modified by Zn and K using equal volume impregnation method. These catalysts were characterized by XRD, NH3-TPD, Py-IR and N2 adsorption-desorption methods. When adding 5% (mass fraction) ZnO to HZSM-5 catalyst, the total acid amount and the ratio of L acid amount to B acid amount become slightly increased. When adding different content of K2O and 5% mass fraction ZnO to HZSM-5 catalyst, the amount of L acid and the ratio of L acid amount to B acid amount are decreasing with the increase of K2O content. The catalytic properties of HZSM-5，Zn/HZSM-5 and K-Zn/HZSM-5 in hydroaromatization were investigated with n-heptane as probe reactant. Results show that the aromatization rate and the selectivities of benzene, toluene and xylene(BTX) increase greatly with the increasing of K when the mass fraction of ZnO is 5% and the mass fraction of K2O is not more than 0.5%， while the selectivity of C9+ aromatics decreases greatly, and the activity and stability of the K-Zn/HZSM-5 catalyst are good.

Key words: HZSM catalyst, hydroaromatization, Zn and K modification, n-heptane