Kinetics and Mechanism of Methanol Conversion over Anatase Titania Nanoshapes
| Autor: | Meijun Li, Guoxiang Hu, Zachary D. Hood, Guo Shiou Foo, Zili Wu, De-en Jiang |
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| Rok vydání: | 2017 |
| Předmět: |
Anatase
Methyl formate Inorganic chemistry Kinetics 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Redox Catalysis 0104 chemical sciences chemistry.chemical_compound chemistry Oxidative coupling of methane Dimethyl ether Methanol 0210 nano-technology |
| Zdroj: | ACS Catalysis. 7:5345-5356 |
| ISSN: | 2155-5435 |
| Popis: | The kinetics and mechanism of methanol dehydration, redox, and oxidative coupling were investigated at 300 °C under dilute oxygen concentration over anatase TiO2 nanoplates and truncated-bipyramidal nanocrystals in order to understand the surface structure effect of TiO2. The two TiO2 nanoshapes displayed both (001) and (101) facets, with a higher fraction of the (001) facet exposed on the nanoplates, while truncated-bipyramidal nanocrystals were dominated by the (101) facet. A kinetic study using in situ titration with ammonia shows that the active sites for methanol dehydration are acidic and nonequivalent in comparison to redox and oxidative coupling. In situ FTIR spectroscopy reveals that adsorbed methoxy is the dominant surface species for all reactions, while the observed methanol dimer is found to be a spectator species through isotopic methanol exchange, supporting the dissociative mechanism for methanol dehydration via surface methoxy over TiO2 surfaces. Density functional theory calculations sho... |
| Databáze: | OpenAIRE |
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