Mechanism and catalytic performance for direct dimethyl ether synthesis by CO2 hydrogenation over CuZnZr/ferrierite hybrid catalyst

Qingtao Sheng; Run-Ping Ye; Weibo Gong; Xiufeng Shi; Bang Xu; Morris Argyle; Hertanto Adidharma; Maohong Fan

doi:10.1016/j.jes.2020.02.015

Mechanism and catalytic performance for direct dimethyl ether synthesis by CO₂ hydrogenation over CuZnZr/ferrierite hybrid catalyst

J Environ Sci (China). 2020 Jun:92:106-117. doi: 10.1016/j.jes.2020.02.015. Epub 2020 Feb 21.

Authors

Qingtao Sheng¹, Run-Ping Ye², Weibo Gong³, Xiufeng Shi¹, Bang Xu⁴, Morris Argyle⁵, Hertanto Adidharma³, Maohong Fan⁶

Affiliations

¹ College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China; Department of Engineering and Applied Science, University of Wyoming, Laramie, WY 82071, USA.
² Department of Engineering and Applied Science, University of Wyoming, Laramie, WY 82071, USA; Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fujian 350002, China; University of Chinese Academy of Sciences, Beijing 100049, China.
³ Department of Engineering and Applied Science, University of Wyoming, Laramie, WY 82071, USA.
⁴ Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China.
⁵ Department of Chemical Engineering, Brigham Young University, UT 84602, USA.
⁶ Department of Petroleum Engineering, University of Wyoming, Laramie, WY 82071, USA; School of Energy Resources, University of Wyoming, Laramie, WY 82071, USA; School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA. Electronic address: mfan@uwyo.edu.

PMID: 32430113
DOI: 10.1016/j.jes.2020.02.015

Abstract

Direct synthesis of dimethyl ether (DME) by CO₂ hydrogenation has been investigated over three hybrid catalysts prepared by different methods: co-precipitation, sol-gel, and solid grinding to produce mixed Cu, ZnO, ZrO₂ catalysts that were physically mixed with a commercial ferrierite (FER) zeolite. The catalysts were characterized by N₂ physisorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption of CO₂ (CO₂-TPD), temperature programmed desorption of NH₃ (NH₃-TPD), and temperature programmed H₂ reduction (H₂-TPR). The results demonstrate that smaller CuO and Cu crystallite sizes resulting in better dispersion of the active phases, higher surface area, and lower reduction temperature are all favorable for catalytic activity. The reaction mechanism has been studied using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Methanol appears to be formed via the bidentate-formate (b-HCOO) species undergoing stepwise hydrogenation, while DME formation occurs from methanol dehydration and reaction of two surface methoxy groups.

Keywords: CO(2) hydrogenation; Dimethyl ether (DME) synthesis; Ether; Mechanism.

MeSH terms

Carbon Dioxide*
Catalysis
Hydrogenation
Methyl Ethers
Oxidation-Reduction

Substances

Methyl Ethers
Carbon Dioxide
dimethyl ether