Identification of C2–C5 products from CO2 hydrogenation over PdZn/TiO2–ZSM-5 hybrid catalysts

Jonathan Ruiz Esquius; Hasliza Bahruji; Michael Bowker; Graham J. Hutchings

doi:10.1039/D0FD00135J

Identification of C₂–C₅ products from CO₂ hydrogenation over PdZn/TiO₂–ZSM-5 hybrid catalysts†

Jonathan Ruiz Esquius,

^a Hasliza Bahruji,

^b Michael Bowker

*^ac and Graham J. Hutchings

*^a

Author affiliations

* Corresponding authors

^a School of Chemistry, Cardiff Catalysis Institute, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
E-mail: Hutch@cardiff.ac.uk, BowkerM@cardiff.ac.uk

^b Centre of Advanced Material and Energy Science, University Brunei Darussalam, Jalan Tungku Link, Gadong BE 1410, Brunei Darussalam

^c Catalysis Hub, RCAH, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, UK

Abstract

The combination of a methanol synthesis catalyst and a solid acid catalyst opens the possibility to obtain olefins or paraffins directly from CO₂ and H₂ in one step. In this work several PdZn/TiO₂–ZSM-5 hybrid catalysts were employed under CO₂ hydrogenation conditions (240–360 °C, 20 bar, CO₂/N₂/H₂ = 1 : 1 : 3) for the synthesis of CH₃OH, consecutive dehydration to dimethyl ether and further oxygenate conversion to hydrocarbons. No significant changes after 36 h reaction on the methanol synthesis catalyst (PdZn/TiO₂) were observed by XRD, XAS or XPS. No olefins were observed, indicating that light olefins undergo further hydrogenation under the reaction conditions, yielding the corresponding alkanes. Increasing the aluminium sites in the zeolites (Si : Al ratio 80 : 1, 50 : 1 and 23 : 1) led to a higher concentration of mild Brønsted acid sites, promoting hydrocarbon chain growth.

This article is part of the themed collection: Carbon dioxide utilisation

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Article information

DOI: https://doi.org/10.1039/D0FD00135J
Article type: Paper
Submitted: 13 Dec 2020
Accepted: 10 Feb 2021
First published: 16 Feb 2021
This article is Open Access

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Faraday Discuss., 2021,230, 52-67

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Identification of C₂–C₅ products from CO₂ hydrogenation over PdZn/TiO₂–ZSM-5 hybrid catalysts

J. Ruiz Esquius, H. Bahruji, M. Bowker and G. J. Hutchings, Faraday Discuss., 2021, 230, 52 DOI: 10.1039/D0FD00135J

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