The Dehydration of Methanol to Dimethyl Ether over a Novel Solid Acid-base Catalyst

Abstract

A novel polymer solid acid-base catalyst Cat-AAA (Al + aminoacetic acid) with aluminum and nitrogen was prepared from aminoacetic acid and Al by using triblock copolymer Pluronic F127 as a template via evaporation induced organic–organic assembly method. Cat-AAA was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectra. The acid-base properties of the catalysts were determined by temperature programmed desorption using CO2 and NH3 as probe molecules. The dehydration of methanol to dimethyl ether over Cat-AAA had been studied; the results showed that the conversion of methanol and selectivity of dimethyl ether is higher at a high reaction temperature. The key requirements for a good catalyst for dehydration of methanol to dimethyl ether are: (i) weak acid-sites activate O in a methanol molecule; (ii) at the same time, weak base-sites activate H of hydroxy group in another methanol molecule.