Bakhtiari, H., Tafreshi, S.S., Torkashvand, M. et al. (2 more authors) (2024) A DFT Study of CO Hydrogenation on Graphene Oxide: Effects of Adding Mn on Fischer-Tropsch Synthesis. Catalysts, 14 (5). 294. ISSN 2073-4344
Abstract
The hydrogenation of carbon monoxide (CO) offers a promising avenue for reducing air pollution and promoting a cleaner environment. Moreover, by using suitable catalysts, CO can be transformed into valuable hydrocarbons. In this study, we elucidate the mechanistic aspects of the catalytic conversion of CO to hydrocarbons on the surface of manganese-doped graphene oxide (Mn-doped GO), where the GO surface includes one OH group next to one Mn adatom. To gain insight into this process, we have employed calculations based on the density functional theory (DFT) to explore both the thermodynamic properties and reaction energy barriers. The Mn adatoms were found to significantly activate the catalyst surface by providing stronger adsorption geometries. Our study concentrated on two mechanisms for CO hydrogenation, resulting in either CH4 production via the reaction sequence CO → HCO → CH2O → CH2OH → CH2 → CH3 → CH4 or CH3OH formation through the CO → HCO → CH2O → CH2OH → CH3OH pathway. The results reveal that both products are likely to be formed on the Mn-doped GO surface on both thermodynamic grounds and considering the reaction energy barriers. Furthermore, the activation energies associated with each stage of the synthesis show that the conversion reactions of CH2 + OH → CH3 + O and CH2O + OH → CH2OH + O with energy barriers of 0.36 and 3.86 eV are the fastest and slowest reactions, respectively. The results also indicate that the reactions: CH2OH + OH → CH2 + O + H2O and CH2OH + OH → CH3OH + O are the most exothermic and endothermic reactions with reaction energies of −0.18 and 1.21 eV, respectively, in the catalytic pathways.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). |
Keywords: | carbon monoxide hydrogenation; CH4; catalyst; Mn-doped graphene oxide; DFT |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 23 Apr 2024 10:14 |
Last Modified: | 13 May 2024 13:12 |
Published Version: | https://www.mdpi.com/2073-4344/14/5/294#:~:text=Th... |
Status: | Published |
Publisher: | MDPI |
Identification Number: | 10.3390/catal14050294 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:211719 |