Synthesis of Al-MTW with low Si/Al ratios by combining organic and inorganic structure directing agents
[EN] A rationalized combination of alkali cations and bulky dicationic organic structure directing agents (OSDAs) has allowed the synthesis of the Al-rich MTW zeolites with Si/Al ratios of similar to 12 and large pore accessibility. Al-27 MAS NMR spectroscopy indicates that most of the aluminum atom...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:riunet.upv.es:10251/78842 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/78842 |
| Access Level: | acceso abierto |
| Palabra clave: | OSDA-Free synthesis Crystal-structure ZSM-12 zeolite Framework Catalysts Systems Beta QUIMICA ORGANICA |
| Sumario: | [EN] A rationalized combination of alkali cations and bulky dicationic organic structure directing agents (OSDAs) has allowed the synthesis of the Al-rich MTW zeolites with Si/Al ratios of similar to 12 and large pore accessibility. Al-27 MAS NMR spectroscopy indicates that most of the aluminum atoms are in tetrahedral coordination in framework positions, and in situ infrared pyridine adsorption/desorption spectroscopy reveals strong Bronsted acidity after cationic exchange for the Al-rich MTW. In addition, another MTW material with a Si/Al ratio of 30 has been synthesized under alkali-free conditions using a bulky dicationic molecule such as OSDA, the lowest Si/Al ratio being achieved for a MTW zeolite synthesized in the absence of alkali-cations in the synthesis media. The catalytic activity of these MTW materials has been tested for the n-decane cracking reaction, achieving higher catalytic activities and olefin yields than other related large pore zeolites. |
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