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Technical University of Crete
Technical University of Crete
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| URI: | http://purl.tuc.gr/dl/dias/F9C1F1C9-2479-4758-9B6F-7544B132CD97 | ||
| Year | 2021 | ||
| Type of Item | Peer-Reviewed Journal Publication | ||
| License |
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| Bibliographic Citation | M. Hatzisymeon, A. Petala, and P. Panagiotopoulou, “Carbon dioxide hydrogenation over supported Ni and Ru catalysts,” Catal. Lett., vol. 151, no. 3, pp. 888–900, Mar. 2021. doi: 10.1007/s10562-020-03355-0 https://doi.org/10.1007/s10562-020-03355-0 | ||
| Appears in Collections |
The catalytic activity of supported Ni and Ru catalysts has been investigated for the CO2 hydrogenation reaction with respect to the nature of the support and operating conditions employed. It has been found that the nature of the metal oxide support affects significantly catalytic performance in a manner which depends strongly on the nature of the dispersed metal. Catalytic activity of Ni increases following the order TiO2 < Al2O3 ~ YSZ < CeO2, contrary to Ru activity, which is significantly improved when supported on TiO2 compared to CeO2, YSZ or Al2O3. Turnover frequency of CO2 conversion and selectivity toward CH4 for Ni/MxOy catalysts are progressively increased with decreasing Ni particle size from 36.1 (for Ni/TiO2) to 8.5 nm (for Ni/CeO2). In contrast, the opposite trend is observed for Ru/MxOy catalysts, where both catalytic activity and selectivity increase with increasing Ru particle size from 2.2 (for Ru/Al2O3) to 4.2 nm (for Ru/TiO2). Results provide evidence that metal dispersion is a key physicochemical parameter determining catalytic activity. Conversion curve of CO2 shifts toward lower temperatures with decreasing gas hourly space velocity or increasing H2:CO2 molar ratio, which is accompanied by an increase of selectivity toward methane. Long-term stability tests conducted over 5%Ni/CeO2 catalyst showed that it is very active, selective and stable for more than 30 h on stream and, therefore, is a promising catalyst for the CO2 methanation reaction.
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