Methanol aromatization over HZSM-5 catalysts modified with different zinc salts

HZSM-5 catalysts modified with various Zn salts, namely zinc sulfate, zinc acetate, zinc nitrate, and zinc chloride, were prepared using an impregnation method. The resultant catalysts were characterized by X-ray diffraction, N-2 adsorption, thermogravimetry-mass spectrometry, temperature-programmed desorption of NH3, and infrared spectroscopy using pyridine as the probe molecule. The methanol-to-aromatic (MTA) performance over the modified catalysts was investigated. The results showed that the type of Zn species in the catalyst significantly influenced the catalyst surface acidity. The distribution of acid sites and Zn species in the HZSM-5 catalyst modified with zinc sulfate effectively improved the MTA performance. (C) 2014, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V.. All rights reserved.