Promoting effect of dual modification of H-ZSM-5 catalyst by alkali treating and Mg doping on catalytic performances for alkylation of benzene with ethanol to ethylbenzene

Abstract

Alkali-treated HZSM-5 zeolite (AT) was modified with Mg species to produce combined modified HZSM-5 catalyst (Mg-AT) for alkylation of benzene with ethanol to ethylbenzene. The catalysts were tested and characterized by X-ray diffraction (XRD), NH₃-Temperature Programmed Desorption (NH₃-TPD), Nitrogen adsorption–desorption, Magic angle spinning nuclear magnetic resonance (MAS NMR) and Scanning Electron Microscope (SEM) techniques. The characterization results showed that for the combined modified HZSM-5 sample, the ratio of surface area of mesopores to the total surface area was the highest. The Mg (1 wt%)-AT catalyst was found to exhibit the highest activity (30% of the conversion of benzene) and selectivity to EB (92%) for the reaction, which was confirmed to be due to the proper L/B acid proportion (3.79) and the improvement of the mesopores of the catalyst.