A Review on Structural Modification of Zeolites for Enhanced Performance in Xylene Isomerization

Structural modification of zeolites has emerged as a novel approach for optimizing catalytic performance in xylene isomerization, playing crucial role in enhancing the efficiency of petrochemical processes. This review examines various zeolite modification strategies, including non-metallic element impregnation (phosphorus and germanium), mesopore engineering, surface modification via silylation, and the tuning of acid site distribution and strength. Recent studies have demonstrated that reducing the number and strength of strong acid sites in modified zeolites, while maintaining an optimal distribution of weak acid sites, enhances para-xylene selectivity and minimizes undesirable side reactions. Additionally, alterations in mesoporous architecture and improved molecular accessibility in modified zeolites contribute to higher conversion rates and better control over reaction mechanisms. Spectroscopic data and molecular dynamics simulations have revealed that structural modifications steer the reaction pathway toward monomolecular isomerization while suppressing the formation of undesired byproducts associated with bimolecular routes. This review explores the impact of these modifications on kinetic parameters, reaction mechanisms, and catalyst stability, providing insights into optimization strategies for achieving superior industrial performance.

Keywords:

Zeolite , Xylene Isomerization , Structural Modification , Reaction Kinetics , Acidity Engineering , Mesoporous Catalysts