(475a) Synthesis of Self-Pillared Zeolite Nanosheets by Repetitive Branching

Zhang, X., University of Minnesota
Liu, D., University of Minnesota
Xu, D., Tsinghua University
Asahina, S., JEOL Ltd.
Agrawal, K. V., University of Minnesota
Al Wahedi, Y., University of Minnesota
Bhan, A., University of Minnesota
Al Hashimi, S., Petroleum Institute
Terasaki, O., KAIST
Thommes, M., Quantachrome Instruments

Hierarchical zeolites is a novel class of catalysts and adsorbents with the typical ordered zeolitic microporosity, as well as mesopores, which by allowing for fast transport of bulky molecules, enable improved performance in petrochemical and biomass processing. Starting with a low-cost structure-directing agent, by one-step hydrothermal crystal growth approach, we synthesized a new hierarchical zeolite composed of perpendicularly connected microporous nanosheets using repetitive branching strategy. Although this strategy has been used in the synthesis of other nanostructures, such as semiconductor tetrapods, it has not been explored for the formation of pillared zeolites. The zeolite nanosheets have thickness of 2 nm and contain micropores typical of pentasil zeolites. The house-of-cards arrangement of the nanosheets creates a permanent network of 2-7 nm mesopores, which, along with the high external surface area and reduced micropore diffusion length, enable higher reaction rates for bulky molecules compared to those of other mesoporous and conventional MFI zeolites.