Effects of Mixing Methods of Bifunctional Catalysts on Catalyst Stability of DME Synthesis via CO₂ Hydrogenation

Author

Shoujie Ren
Shiguang Li
Naomi Klinghoffer
Miao Yu
Xinhua Liang, Missouri University of Science and TechnologyFollow

Abstract

The effects of three different mixing methods of CuO/ZnO/Al₂O₃ (CZA) and HZSM-5 bifunctional catalyst on the stability for dimethyl ether (DME) synthesis from carbon dioxide (CO₂) hydrogenation were investigated. When the bifunctional catalyst was prepared by method A (mixing powder without pelletization), there was no significant change in DME production and catalyst stability when the HZSM-5 loading was varied between 0.1 g and 0.5 g with a fixed CZA loading of 0.5 g,. When the bifunctional catalysts were prepared by method B (pressed into pellets of CZA and pellets of HZSM-5 and then mixed) and method C (mixed CZA and HZSM-5 powders, then pressed into pellets), the mixing methods did not initially impact CO₂ conversion and had a minor effect on DME yield. However, long-term tests (100 h) indicated that the mixing method had a significant influence on the catalyst stability. Method B showed the best stability and the extent of catalyst deactivation followed the sequence of method B < method A < method C. Characterizations of spent catalysts indicated that method B could reduce the extent of copper (Cu) oxidation, which due to the relatively low surface contact between Cu active sites and HZSM-5. Large amounts of water generated in CO₂ hydrogenation to synthesize DME and intimate contact between CZA and HZSM-5 catalyst could induce severe oxidation of Cu and metal ions migration from hydrogenation catalyst to HZSM-5, which can result in the number reduction of acidic sites.

Recommended Citation

S. Ren et al., "Effects of Mixing Methods of Bifunctional Catalysts on Catalyst Stability of DME Synthesis via CO₂ Hydrogenation," Carbon Resources Conversion, vol. 2, no. 1, pp. 85 - 94, KeAi Communications Co. Ltd., Jan 2019.

The definitive version is available at https://doi.org/10.1016/j.crcon.2019.03.002

Department(s)

Chemical and Biochemical Engineering

Research Center/Lab(s)

Intelligent Systems Center

Comments

This work was supported by the U.S. Department of Energy through contract DE-AR0000806.

International Standard Serial Number (ISSN)

2588-9133

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2019 The Authors, All rights reserved.

Creative Commons Licensing

This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Publication Date

01 Jan 2019