CO2 Hydrogenation on NixMg1−xAl2O4: A Comparative Study of MgAl2O4 and NiAl2O4
| Autor: | Eun Hee Ko, Jinho Boo, Dohyung Kang, Minkyu Kim, Boseok Seo, No-Kuk Park |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Precipitation (chemistry) Chemical technology TP1-1185 CO2 methanation Catalysis Methane Chemistry chemistry.chemical_compound magnesium aluminate Adsorption chemistry Chemical engineering Methanation Desorption nickel aluminate Density functional theory Physical and Theoretical Chemistry Selectivity QD1-999 CO2 hydrogenation CO2 conversion |
| Zdroj: | Catalysts Volume 11 Issue 9 Catalysts, Vol 11, Iss 1026, p 1026 (2021) |
| ISSN: | 2073-4344 |
| DOI: | 10.3390/catal11091026 |
| Popis: | Due to the increasing attention focused on global warming, many studies on reducing CO2 emissions and developing sustainable energy strategies have recently been performed. One of the approaches is CO2 methanation, transforming CO2 into methane. Such transformation (CO2 + 4H2 → CH4 + 2H2O) provides advantages of carbon liquification, storage, etc. In this study, we investigated CO2 methanation on nickel–magnesium–alumina catalysts both experimentally and computationally. We synthesized the catalysts using a precipitation method, and performed X-ray diffraction, temperature-programmed reduction, and N2 adsorption–desorption tests to characterize their physical and chemical properties. NiAl2O4 and MgAl2O4 phases were clearly observed in the catalysts. In addition, we conducted CO2 hydrogenation experiments by varying with temperatures to understand the reaction. Our results showed that CO2 conversion increases with Ni concentration and that MgAl2O4 exhibits high selectivity for CO. Density functional theory calculations explained the origin of this selectivity. Simulations predicted that adsorbed CO on MgAl2O4(100) weakly binds to the surface and prefers to desorb from the surface than undergoing further hydrogenation. Electronic structure analysis showed that the absence of a d orbital in MgAl2O4(100) is responsible for the weak binding of CO to MgAl2O4. We believe that this finding regarding the origin of the CO selectivity of MgAl2O4 provides fundamental insight for the design methanation catalysts. |
| Databáze: | OpenAIRE |
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