Cao, Jingxian, Lewis, Richard J., Qi, Guodong, Bethell, Donald, Howard, Mark J., Harrison, Brian, Yao, Bingqing, He, Qian, Morgan, David J. ORCID: https://orcid.org/0000-0002-6571-5731, Ni, Fenglou, Sharma, Pankaj ORCID: https://orcid.org/0000-0003-2319-260X, Kiely, Christopher J. ORCID: https://orcid.org/0000-0001-5412-0970, Li, Xu, Deng, Feng, Xu, Jun and Hutchings, Graham J. ORCID: https://orcid.org/0000-0001-8885-1560 2023. Methane conversion to methanol using Au/ZSM-5 is promoted by carbon. ACS Catalysis 13 (11) , pp. 7199-7209. 10.1021/acscatal.3c01226 |
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Abstract
The oxidation of methane using molecular oxygen as the terminal oxidant, over a Au/ZSM-5 catalyst, has been previously shown to produce methanol and acetic acid as products. We now show that this reaction is significantly enhanced by the addition of a range of carbon additives. Isotopic 13C-labeled studies and corresponding investigation into the activity of the carbon materials alone reveal that nearly all the methanol produced is derived from methane oxidation, with a negligible contribution attributed to the carbon additives, while further study identified carbon as the primary source of acetic acid, which was observed as a minor product. Gas phase CO is not observed as a product in the reaction of Au/ZSM-5 with CH4 + O2, and in reactions with added CO, not all the CO is converted. We, therefore, conclude that the effect observed with the carbon additive is not due to the in situ production of gas phase CO as a reaction intermediate. Rather, we postulate that the effect derives from the oxidation of the surface of the carbon in the aqueous reaction mixture and the interaction of the oxidized carbon surface with Au/ZSM-5. The reactivity of carbon in this reaction at 240 °C is unexpected, and the presence of water is required to observe the effect.
Item Type: | Article |
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Date Type: | Publication |
Status: | Published |
Schools: | Chemistry Cardiff Catalysis Institute (CCI) |
Publisher: | American Chemical Society |
ISSN: | 2155-5435 |
Funders: | Cardiff University and the Max Planck Centre for Fundamental Heterogeneous Catalysis (FUNCAT) |
Date of First Compliant Deposit: | 19 May 2023 |
Date of Acceptance: | 27 April 2023 |
Last Modified: | 05 Jan 2024 04:44 |
URI: | https://orca.cardiff.ac.uk/id/eprint/159741 |
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