Synthesis of Hierarchical ZSM-5 Zeolite Mesocrystals with Controllable Macropores toward Enhanced Catalytic...

Zeolite mesocrystals are ordered assemblies of nanosized building units that integrate microporosity, interconnected mesoporosity, and high crystallinity within a single material, thereby offering significant advantages for heterogeneous catalysis. However, the construction of zeolite mesocrystals with macropores remains highly challenging because of the complexity of crystallization and assembly processes. In this work, we demonstrate a novel strategy to synthesize hierarchical ZSM-5 zeolite mesocrystals with tunable macropores (HM-ZSM-5) by using tetrapropylammonium hydroxide (TPAOH) and tetraethylammonium hydroxide (TEAOH) as dual structure-directing agents. Time-dependent SEM, XRD, and solid-state magic-angle spinning NMR (27Al and 29Si) methods are used to investigate the formation mechanism of HM-ZSM-5. Fluorescence experiments and catalytic evaluations demonstrate that the interconnected micro-meso-macroporous architecture of HM-ZSM-5 significantly improves molecular diffusion and catalytic performance. This work provides new insights into the rational design of hierarchical zeolites with highly interconnected pore systems for enhanced mass transport in zeolite-based catalysis.