TY - JOUR
T1 - Atomic locations and adsorbate interactions of Al single and pair sites in H-ZSM-5 zeolite
AU - Li, Guangchao
AU - Foo, Christopher
AU - Fan, Raymond
AU - Zheng, Mingji
AU - Wang, Qiang
AU - Chu, Yueying
AU - Li, Jiasi
AU - Day, Sarah
AU - Steadman, Paul
AU - Tang, Chiu
AU - Lo, Tsz Woon Benedict
AU - Deng, Feng
AU - Tsang, Shik Chi Edman
N1 - Publisher Copyright:
Copyright © 2025 the authors, some rights reserved.
PY - 2025/1/23
Y1 - 2025/1/23
N2 - The distribution of substitutional aluminum (Al) atoms in zeolites affects molecular adsorbate geometry, catalytic activity, and shape and size selectivity. Accurately determining Al positions has been challenging. We used synchrotron resonant soft x-ray diffraction (RSXRD) at multiple energies near the Al K-edge combined with molecular adsorption techniques to precisely locate "single Al" and "Al pairs" in a commercial H-ZSM-5 zeolite. This analysis depicts three distinct Al tetrahedral (T) sites: T8, T6, and T4. A combined suite of characterizations, including ammonia temperature-dependent desorption, neutron powder diffraction, solid-state nuclear magnetic resonance spectroscopy, and density functional theory calculations, reveal isolated ammonia adsorption on T8 as "single Al" in the straight channel and bridged ammonia adsorption on T6 and T4 as an "Al pair" (AlT6-O-SiT5-O-AlT4) in the straight-sinusoidal intersection.
AB - The distribution of substitutional aluminum (Al) atoms in zeolites affects molecular adsorbate geometry, catalytic activity, and shape and size selectivity. Accurately determining Al positions has been challenging. We used synchrotron resonant soft x-ray diffraction (RSXRD) at multiple energies near the Al K-edge combined with molecular adsorption techniques to precisely locate "single Al" and "Al pairs" in a commercial H-ZSM-5 zeolite. This analysis depicts three distinct Al tetrahedral (T) sites: T8, T6, and T4. A combined suite of characterizations, including ammonia temperature-dependent desorption, neutron powder diffraction, solid-state nuclear magnetic resonance spectroscopy, and density functional theory calculations, reveal isolated ammonia adsorption on T8 as "single Al" in the straight channel and bridged ammonia adsorption on T6 and T4 as an "Al pair" (AlT6-O-SiT5-O-AlT4) in the straight-sinusoidal intersection.
UR - https://www.scopus.com/pages/publications/85216718239
U2 - 10.1126/science.adq6644
DO - 10.1126/science.adq6644
M3 - Journal article
C2 - 39847623
AN - SCOPUS:85216718239
SN - 0036-8075
VL - 387
SP - 388
EP - 393
JO - Science (New York, N.Y.)
JF - Science (New York, N.Y.)
IS - 6732
ER -