Enhanced Stability of Fe-Modified Cuo-Zno-Zro₂-Al₂O₃/HZSM-5 Bifunctional Catalysts for Dimethyl Ether Synthesis from Co₂ Hydrogenation

Abstract

A series of iron (Fe) modified CuO-ZnO-ZrO2-Al2O₃ (CZZA) catalysts, with various Fe loadings, were prepared using a co-precipitation method. A bifunctional catalyst, consisting of Fe-modified CZZA and HZSM-5, was studied for dimethyl ether (DME) synthesis via CO2 hydrogenation. The effects of Fe loading, reaction temperature, reaction pressure, space velocity, and concentrations of precursor for the synthesis of the Fe-modified CZZA catalyst on the catalytic activity of DME synthesis were investigated. Long-term stability tests showed that Fe modification of the CZZA catalyst improved the catalyst stability for DME synthesis via CO2 hydrogenation. The activity loss, in terms of DME yield, was significantly reduced from 4.2% to 1.4% in a 100 h run of reaction, when the Fe loading amount was 0.5 (molar ratio of Fe to Cu). An analysis of hydrogen temperature programmed reduction revealed that the introduction of Fe improved the reducibility of the catalysts, due to assisted adsorption of H2 on iron oxide. The good stability of Fe-modified CZZA catalysts in the DME formation was most likely attributed to oxygen spillover that was introduced by the addition of iron oxide. This could have inhibited the oxidation of the Cu surface and enhanced the thermal stability of copper during long-term reactions.

Department(s)

Chemical and Biochemical Engineering

Research Center/Lab(s)

Intelligent Systems Center

Comments

U.S. Department of Energy, Grant DE-AR0000806

Keywords and Phrases

CO2 hydrogenation; Cu-ZnO based catalyst; Dimethyl ether (DME); Iron (Fe); Stability

International Standard Serial Number (ISSN)

1004-9541

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2021 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd., All rights reserved.

Publication Date

01 Oct 2021

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