Engineering growth defects: A new route towards hierarchical ZSM-5 zeolite with high-density intracrystalline mesopores

Hierarchical zeolites are promising solid acid catalysts for industrial processes and conversions of bulky molecules because they provide fast mass transfer along with size and shape selectivity; however, their synthesis always involves either complicated post-synthetic modifications or cost-intensive templates. In this work, engineering growth defects has been developed as a new and efficient strategy for preparing hierarchical ZSM-5 zeolite with high specific surface area and abundant uniform intracrystalline mesopores. This route only involved certain energy-efficient conditions, e.g., tender crystallization and mesotemplate-free conditions. Combining tender crystallization conditions with an optimal original Si/Al ratio (150-300) in a colloid synthesis system was found to be the key to successfully engineer the growth defects. Importantly, it even exhibited higher catalytic activities for benzaldehyde-alcohol condensation reactions than mesoporous ZSM-5 zeolite prepared using mesoscale templates.