Synthesis characterization and catalytic evaluation of modified nanocrystalline zeolites

Abstract

Nano dimensions unveil a canvas of limitless possibilities.Decreasing the size of zeolite crystals to nanometer dimensionsimproves their characteristics by boosting surface area andminimizing diffusion path length. Research is focused on preparingzeolites with dispersed metal ions, especially high-silica zeolites,which are applauded for their effectiveness as catalysts in variouschemical reactions. The development of hierarchical zeolites withsecondary pore structures has been notable over the last decade.Additionally, zeolites doped with extra framework cations are foundto exhibit excellent dielectric properties. This study investigates thefundamental aspects of metals in zeolites and hierarchical zeolitestructures, discussing their applications for catalyzing reactions. Thesynthesized zeolites undergo a thorough characterization by FTIR,XRD, FESEM, UV-Visible spectroscopy, surface area, and surfaceacidity measurement. Furthermore, a comprehensive investigationinto the sustainable catalytic reactions facilitated by these metal-modified zeolites, analyzing how metals in zeolites impact theselective acetylation of toluene under minimal experimentalconditions. The study showcases innovative strategies for enhancingthe catalytic activity through developing hierarchical porosity innanocrystalline ZSM-5 and beta. Adding PMMA during nucleationminimizes internal defective silanols and successfully createshierarchically porous ZSM-5 zeolite. However, the zeolite beta synthesized with PMMA addition features narrowly distributedmesopores and microporous structure. This study also evaluates theeffectiveness of hierarchical ZSM-5 and zeolite beta in the selectiveacetylation of2-MON.Improved homogeneity of mesoporefeatures and active site environments enhances selective catalyticbehavior, highlighting the significance of heteroporous structures inzeolite catalysis. The study delves into the dielectric characteristicsof cerium-doped zeolite beta employing broadband spectroscopicmethods. The introduction of cerium induces significant variationsin dielectric readings, leading to remarkably high dielectric constantscompared to unmodified zeolite beta. Insights gained fromimpedance and modulus analyses contribute to the progression ofzeolite-based charge storage device technologies.The studysuggests that the research could lead to improvements in fixingdefects in zeolites and in making specific organic compounds formedicines using zeolite catalysts. It also hints at potential uses forzeolites as dielectric materials. Understanding the dielectricproperties of zeolites provides crucial insights for researchers andengineers to design applications beyond catalysis.