Ultrathin ZSM-5 zeolite nanocrystals synthesized from purely inorganic precursors

Ultrathin zeolite nanocrystals offer distinct advantages in catalysis, adsorption, and separation due to their enhanced exposure of crystal facets and improved molecular diffusion. The synthesis of ultrathin zeolites via template-free and additive-free approaches is highly desirable for sustainable and scalable production, yet remains a longstanding challenge. ZSM-5 nanosheets with a b-axis thickness as small as 10 nm were synthesized via seed-assisted crystallization in a purely inorganic aluminosilicate medium, without the use of organic templates, fluoride, or other additives. The influence of Silicalite-1 seed treatment history, a previously overlooked parameter on ZSM-5 crystallization was systematically investigated. The presence or absence of occluded organic template within the seeds critically modulates crystal morphology by affecting surface dissolution and secondary nucleation at the seed surface. Catalytic testing in methanol conversion indicates that, although structural variations due to nanoscale dimensions are minimal, differences in crystal morphology significantly influence catalytic selectivity. These findings underscore the crucial role of morphology control in tailoring the catalytic performance of zeolites.