Catalytic Application of Mesoporous ZSM-5 Zeolite

The recent progress, particularly in this decade, in catalytic applications of mesoporous ZSM-5 was reviewed. Mesoporous ZSM-5 materials aim to combine the shape-selectivity from micropores of ZSM-5 with enhanced mass transportation from the additional mesoporosity in catalytic reactions. The reactions discussed in this review are classified into two types: (1) the reactions mainly occurred on the external surface or in the pore mouths of the mesoporous ZSM-5 and (2) the reactions mainly occurred in micropores of ZSM-5. The external acid sites of mesoporous ZSM-5 enable the reactions involving bulky reactants that exceed the size of ZSM-5 micropores; and the presence of mesoporosity which improves the mass transport of reactants as well as products, reduces diffusion limitation and accelerates catalytic reaction. Although the advantages of mesoporous ZSM-5 compared with the conventional one are closely related to high external surface area and large mesopore volume, the acidity, including the type, strength and amount of acid sites and Al distribution, should be taken into account when the mesoporous ZSM-5 is utilized as catalyst in a real reaction. Finally, future challenges and opportunities for mesoporous ZSM-5 materials are presented.