Synthesis of Self-Pillared Zeolite Nanosheets by Repetitive Branching
Xueyi Zhang, Dongxia Liu, Dandan Xu, Shunsuke Asahina, Katie A. Cychosz, Kumar Varoon Agrawal, Yasser Al Wahedi, Aditya Bhan, Saleh Al Hashimi, Osamu Terasaki, Matthias Thommes, Michael Tsapatsis
Science 29 June 2012:
Vol. 336 no. 6089 pp. 1684-1687
Hierarchical zeolites are a class of microporous catalysts and adsorbents that also contain mesopores, which allow for fast transport of bulky molecules and thereby enable improved performance in petrochemical and biomass processing. We used repetitive branching during one-step hydrothermal crystal growth to synthesize a new hierarchical zeolite made of orthogonally connected microporous nanosheets. The nanosheets are 2 nanometers thick and contain a network of 0.5-nanometer micropores. The house-of-cards arrangement of the nanosheets creates a permanent network of 2- to 7-nanometer mesopores, which, along with the high external surface area and reduced micropore diffusion length, account for higher reaction rates for bulky molecules relative to those of other mesoporous and conventional MFI zeolites.