Rapid Fabrication of ZSM-5/AlPO4-5 Composites via Microwave-Ionothermal Strategy for Enhanced Methanol-to-Olefins Catalysis

Microwave-assisted ionothermal strategies offer an effective pathway for rapid zeolite crystallization under mild conditions, while conventional ionothermal approaches are still constrained by prolonged crystallization cycles that limit their industrial applicability. Herein, we report a microwave-activated, ionic liquid-mediated synthesis strategy that enables the precise modulation of crystallization kinetics and composite assembly. By introducing ZSM-5 seeds into the ionic liquid system, the nucleation and growth of AlPO4-5 were significantly accelerated, reducing crystallization time by up to 75% (optimal condition: 60 min). Among various imidazolium-based ionic liquids, [BMMIm]Br demonstrated an optimal balance of hydrophilic and hydrophobic interactions, yielding composite zeolites with high surface area (350 m2·g−1) and large pore volume (0.28 cm3·g−1). Comprehensive characterization (XRD, SEM-EDX, NH3-TPD) confirmed the formation of well-defined ZSM-5/AlPO4-5 core–shell structures and revealed tunable acid site distributions depending on the ionic liquid used. In methanol to olefins (MTO) reactions, the composite catalyst exhibited outstanding selectivity towards light olefins (C2=–C4=: 72.84%), markedly outperforming the individual ZSM-5 and AlPO4-5 components. The superior catalytic behavior is primarily attributed to the synergistic effect of hierarchical acid site tuning and the integrated core–shell architecture, which together optimize reaction selectivity. This strategy provides a promising route for the rational design of high-performance zeolites with significant industrial applicability.