Evaluation of H-BEA Zeolite Dealumination and Adsorption Study of Alkylaromatics in Commercial Y-Type Zeolites

This undergraduate thesis investigates the effects of dealumination strategies on the structural, acidic, and adsorption properties of H-BEA and HY zeolites, with relevance to catalytic processes in hydrocarbon conversion and sustainable fuel production. Two chemical treatments, aqueous HCl and Na₂H₂EDTA (0.13–0.24 M) were evaluated to compare their selectivity toward extra-framework aluminum (EFAL) removal, framework preservation, and modification of acid-site distribution.

The materials were characterized using ICP-OES, XRD, N₂ physisorption (BET), and NH₃-TPD, enabling quantitative assessment of framework Al, external surface area, pore accessibility, and Brønsted/Lewis acidity. Results show that EDTA selectively extracts EFAL with minimal lattice degradation, while HCl causes partial framework dissolution, decreased crystallinity, and significant loss of microporosity.

Also, adsorption behavior was examined through temperature-programmed desorption (TPD) of benzene and toluene in HY zeolite using a differential fixed-bed reactor coupled to mass spectrometry. Gaussian deconvolution of TPD profiles and dilution-bed corrections (SiC) revealed heterogeneous adsorption sites and transport limitations associated with pore topology.

Overall, the thesis demonstrates the mechanistic distinctions between chelating and acidic dealumination routes, their impact on zeolite acidity and structure, and the implications for adsorption–desorption phenomena in alkylaromatic systems. These results contribute to the understanding of zeolite modification strategies for catalytic applications, including ethanol-to-jet (ETJ) conversion and other hydrocarbon upgrading pathways.