Tuning the mesoporosity and Lewis acidity in a beta zeolite by post-synthesis strategies: potential to be used as adsorbent of bulky organic molecules

Tuning the mesoporosity and Lewis acidity in a beta zeolite by post-synthesis strategies: potential to be used as adsorbent of bulky organic molecules

• Autor
• Mateus Gonçalves dos Santos
• Co-autores
• Ernesto Antonio Urquieta-Gonzalez
• Resumo

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  Industrial operations, including the combustion of fossil fuels, have generated large amounts of CO₂ and others dangerous organic compounds that have led to serious environment problems affecting the human life and the flora and fauna. The adsorption of these organic contaminants on solids with appropriate physical and chemical properties is an effective and practical strategy to their abatement. In this regard, the adsorption of those compounds, the most having large kinetic diameters, could be promoted over zeolitic systems having intra and/or intercrystalline mesopores. The presence of intracrystalline mesoporous could diminish the diffusion constraints inside of the zeolite microporous, system then improving the diffusion and consequently favoring the molecules adsorption, which is also promoted on Lewis acid sites. With this objective in mind, we modified a beta zeolite (Si/Al=11.3) by post-synthesis treatments to generate mesoporosity by the removal of Al or Si atoms from the zeolite structure with subsequent isomorphic incorporation of Zr atoms to generate Lewis acidity. The obtained desilicated or dealuminated Zr-HBeta zeolites were characterized by X-ray diffraction, nitrogen physisorption measurements and FTIR of in situ adsorbed pyridine. The result showed that dealumination with further Zr incorporation was the most suitable procedure to obtain a acidic beta zeolite with potential properties to be used as an organic adsorbent.

   

• Palavras-chave
• Beta zeolite, Mesoporous, Zirconium Incorporation, Lewis Acidity, Adsorption of Organic Molecules
• Área Temática
• Sintese e Caracterização