Resolving Complex K-Pt-Sn Interactions in PtSn@K-MFI Catalysts for Alkane Dehydrogenation
[EN] K and Sn contents were rationalized during the synthesis of PtSn@K-MFI to maximize metal dispersion and stability along the MFI crystallites. Experimental results and theoretical calculations reveal a stoichiometry of similar to 1 K per unit cell of MFI, limiting then the final K incorporation...
| Autores: | , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:dnet:riunet______::1b8dde5275cffb68acf8cf45571c489b |
| Acceso en línea: | https://riunet.upv.es/handle/10251/234894 |
| Access Level: | acceso abierto |
| Palabra clave: | Catalysts Crystals Deactivation Platinum Zeolites 07.- Asegurar el acceso a energías asequibles, fiables, sostenibles y modernas para todos 13.- Tomar medidas urgentes para combatir el cambio climático y sus efectos |
| Sumario: | [EN] K and Sn contents were rationalized during the synthesis of PtSn@K-MFI to maximize metal dispersion and stability along the MFI crystallites. Experimental results and theoretical calculations reveal a stoichiometry of similar to 1 K per unit cell of MFI, limiting then the final K incorporation within siliceous MFI crystals at similar to 0.7 wt %. Above this stoichiometry, K is not incorporated into the final solids unless significant amounts of Sn are simultaneously present, leading to the formation of tin-silicate precipitates. The optimized PtSn@K-MFI catalysts improve the catalytic performance of well-established references, as PtSn/SiO2, for the propane dehydration (PDH) reaction. In particular, low Sn loadings (below 0.5 wt %) result in higher time-on-stream (TOS) deactivation catalytic profiles but excellent regenarability after consecutive PDH reaction, while higher Sn content (close to 1 wt %) minimizes TOS deactivation due to the maximization of Pt-Sn bonds but consecutive regenerations result in significant metal sintering. Increasing Sn contents within MFI crystallites facilitates Pt sintering and, thus, occurring catalyst deactivation upon regeneration cycles. As a result of complex interconnected nucleation/crystallization processes, fine-tuning rationalizations of one-pot synthesis approaches can substantially influence the final atomic and subnanometric metal interactions and, consequently, the catalytic and sintering-resistance properties when exposed to highly demanding industrial conditions. |
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