Communications

Comparative study of methanol and dimethyl ether conversions to light olefins over a Mg–HZSM-5/Al₂O₃ catalyst in nitrogen and syngas atmospheres

K. B. Golubev, E. E. Kolesnikova, T. I. Batova, E. N. Khivrich, O. V. Arapova, N. V. Kolesnichenko

A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 119991 Moscow, Russian Federation

Abstract: At low temperatures (300–320 °C), on a Mg–HZSM-5/Al₂O₃ catalyst, dimethyl ether provides a higher yield of light olefins than methanol, but its conversion is strongly suppressed in a syngas atmosphere compared with an inert nitrogen environment. In situ diffuse reflectance infrared Fourier transform spectroscopy revealed that this suppression is attributed to CO-induced carbonylation side reactions resulting in the formation of methyl acetate and acetic acid depleting Brønsted acid sites. Efficient olefin production requires temperatures above 350 °C to mitigate the carbonylation inhibition.

Keywords: dimethyl ether, methanol, light olefins, syngas, Mg–HZSM-5/Al₂O₃ catalyst, carbonylation inhibition, in situ diffuse reflectance infrared Fourier transform spectroscopy.

Received: 22.07.2025
Accepted: 21.10.2025

Language: English

DOI: 10.71267/mencom.7881