Continuous-flow chemoselective reduction of cyclohexanone in a monolithic silica-supported Zr(OPri)4 multichannel microreactor
| Autor: | Katarzyna Maresz, Julita Mrowiec-Białoń, Agnieszka Ciemięga |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Zirconium
Materials science Inorganic chemistry Cyclohexanone chemistry.chemical_element 02 engineering and technology General Chemistry Porosimetry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences Catalysis Thermogravimetry chemistry.chemical_compound Adsorption chemistry Mechanics of Materials General Materials Science Cubic zirconia Microreactor 0210 nano-technology Nuclear chemistry |
| Zdroj: | Microporous and Mesoporous Materials. 252:140-145 |
| ISSN: | 1387-1811 |
| DOI: | 10.1016/j.micromeso.2017.06.023 |
| Popis: | Meerwein-Ponndorf-Vereley reduction of cyclohexanone using 2-butanol as hydrogen donor was studied in the multichannel monolithic silica microreactors modified with zirconium species to demonstrate their higher efficacy than of conventional batch systems with powdered catalysts. Zr(OPr i ) 4 species were attached onto the monoliths siliceous surface to obtain a nominal Zr/Si mass ratio in the range of 0.01–0.28. The value of 0.14 gave the largest concentration of Lewis acid sites and hence also the highest conversion (88%) after 20 min reaction/residence time and productivity of 2.22 mmol/g h. The monoliths prepared by the sol-gel process combined with phase separation were characterized using nitrogen adsorption, mercury porosimetry, thermogravimetry, SEM, FTIR and UV–Vis spectroscopy, pyridine adsorption and XRD. They featured very open 3D co-continuous structure of 20 nm textural meso- and flow-through macropores 30–60 μm in diameter (4 cm 3 /g total pore volume) which was not appreciably changed after their modification with zirconium species. Diffraction peaks characteristic for crystalline zirconia were not detected even in materials with the highest Zr content. |
| Databáze: | OpenAIRE |
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