# Comparative study of the catalytic performance of physically mixed and sequentially utilized γ-alumina and zeolite in methanol-to-propylene reactions

## TL;DR

This paper compares the performance of γ-alumina and zeolite in converting methanol to propylene, finding that their physical mixture works best.

## Contribution

The first documented use of γ-alumina and zeolite together in methanol-to-propylene reactions.

## Key findings

- Physically mixed γ-Al2O3 and H-ZSM-5 zeolite showed highest catalytic activity at 400°C.
- Mesoporous γ-Al2O3 was successfully prepared using sol–gel and hydrothermal methods.
- Methanol conversion and product selectivity were analyzed using gas chromatography.

## Abstract

This study aimed to investigate the catalytic performance of H-ZSM-5 zeolite compared with physically mixed and sequentially used synthesized γ-alumina and zeolite in the methanol-to-propylene (MTP) reaction. A facile, green and cost-effective method was first applied to prepare a mesoporous γ-Al2O3 support using a combination of sol–gel and hydrothermal methods via a few consecutive steps. This process was carried out using aluminium nitrate and polyethylene glycol with different molecular weights as non-ionic surfactants. X-ray diffraction, transmission electon microscopy, thermogravimetric analysis, ammonia temperature programmed desorption and Brunauer–Emmett–Teller analysis were then used to characterize the prepared γ-Al2O3 catalyst. Afterwards, the catalytic activity of the commercial H-ZSM-5 zeolite (Si/Al = 200) and the effect of the presence of the γ-alumina physically mixed and unmixed with the zeolite were also researched in the MTP reaction. Accordingly, methanol conversion and product selectivity were monitored via gas chromatography. The physically mixed mesoporous γ-Al2O3 and H-ZSM-5 zeolite exhibited the highest catalytic activity in terms of both conversion and selectivity at 400°C. To our knowledge, this research represents the first documented use of γ-alumina and zeolite simultaneously as catalysts in the MTP reaction within the English literature. It is hoped that this work will offer valuable insights for advancing the development of catalytic systems in methanol conversion processes.