Tailoring the framework aluminum arrangement in ZSM-5 zeolite to regulate reaction route for alkylation of benzene with methanol

Abstract

Aluminum (Al) arrangement, as a description of distance between the framework Al atoms, can be categorized as the proximity (Alp) and isolation (Ali) states in the zeolite cage, which may change the local hydrophilicity and determine the adsorption capacity in the pores of zeolite. Herein, a phase-transfer method was employed to tailor the framework Al arrangement, which were beneficial to enhance the catalytic performance in alkylation of benzene and methanol. The samples were characterized to verify their Al arrangement and evaluated on the alkylation of benzene with methanol. The conversion of benzene and the selectivity of xylene was significantly improved in the zeolite with more Ali. Furthermore, in-situ IR spectroscopy demonstrated that the adsorption capacity of benzene and methanol influenced by the Al arrangement was the main reason for the enhancement of alkylation. Also, 2D IR correlation maps further illustrated that the improvement of the alkylation is the result of the preference in different reaction routes.