Conversion of Carbon Monoxide into Methanol on Alumina-Supported Cobalt Catalyst: Role of the Support and Reaction Mechanism—A Theoretical Study
| Autor: | Nguyen Thi Thu Ha, Nguyen Binh Long, Le Minh Cam, Nguyen Ngoc Ha |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Reaction mechanism
Hydrogen mechanism chemistry.chemical_element 02 engineering and technology lcsh:Chemical technology 010402 general chemistry Photochemistry 01 natural sciences Catalysis Dissociation (chemistry) lcsh:Chemistry chemistry.chemical_compound Adsorption Al2O3 lcsh:TP1-1185 Physical and Theoretical Chemistry density functional theory methanol support Co4 cluster 021001 nanoscience & nanotechnology 0104 chemical sciences lcsh:QD1-999 chemistry adsorption Density functional theory Methanol 0210 nano-technology Carbon monoxide |
| Zdroj: | Catalysts Volume 9 Issue 1 Catalysts, Vol 9, Iss 1, p 6 (2018) |
| ISSN: | 2073-4344 |
| DOI: | 10.3390/catal9010006 |
| Popis: | Density functional theory (DFT) was used to calculate the step-by-step hydrogenation of carbon monoxide (CO) to form methanol over a Co4 cluster/Al2O3 surface. A three-dimensional Co4 tetrahedral structure was selected to explore its interaction with the supporting Al2O3 (104) surface. Co4 chemically reacted with Al2O3 to form a new chemical system. The calculated results show that Al2O3 support has strengthened the Co4 catalyst during the reaction since the formation of the Co&ndash O bond. Loading Co4 on the Al2O3 surface increases CO adsorption ability but decreases the dissociation ability of C&ndash O to produce hydrocarbons. As such, CH3OH formation becomes more favorable both kinetically and thermodynamically on Co4/Al2O3. In CO hydrogenation, methanol was synthesized through a CO reaction with hydrogen via either an Eley&ndash Rideal or Langmuir&ndash Hinshelwood pathway to form the intermediates C*-O-H, H-C*-OH, H2-C*-OH, and finally the hydrogenation of H2-C*-OH to methanol with both hydrogenation steps forming C*-OH and final product as rate-limiting. These results showed that the interaction between Co, Al2O3 and H2 pressure can change the pathway of CO hydrogenation on Co/Al2O3 and it may, therefore, influence distribution of the final products. |
| Databáze: | OpenAIRE |
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