The structural, infrared (IR) and Raman spectroscopic properties of alkali-metal exchanged (Na+, K+, Rb+, Cs+) zeolites with the stilbite (STI) framework have been studied by Rietveld analysis of high-resolution synchrotron X-ray powder diffraction data, micro-Raman and synchrotron IR spectroscopy at ambient conditions. Ordered arrangements of the extra-framework cations (EFCs) and H2O molecules were found at the intersection of the 10- and 8-ring channels as well as framework distortions and deformations of the channel system caused by the EFCs distributions. The T(5)-T(5) distances along the chains of the structural building units range from 8.921(1) to 8.979(5) Å and scale with the size of EFCs in Na-, K-, Rb-, Cs-STI. Furthermore, our spectroscopic studies show a systematic increase of characteristic band frequencies for the 4- and 5-ring breathing vibration modes in the far-IR spectral region with the size of the EFCs. The frequencies of the ring vibrational bands in the IR and Raman spectra are very sensitive to the presence of specific EFCS, and framework distortion.
Bibliographical noteFunding Information:
This work was supported by the Global Research Laboratory ( NRF-2009-00408 ) and National Research Laboratory ( NRF-2015R1A2A1A01007227 ) Programs of the Korean Ministry of Science, ICT and Planning (MSIP) . The use of the U2A beamline at the National Synchrotron Light Source beamline is supported by COMPRES, the Consortium for Materials Properties Research in Earth Sciences under NSF Cooperative Agreement EAR 06-49658 and by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences , under Contract No. DE-AC02-98CH10886 . Y.M. thanks the support from the BK21Plus Institute of Earth, Astronomy, and Atmospheric Sciences of Yonsei University , and the National Natural Science Foundation of China (Grant 11304114 ). T.V. thanks the Australian Nuclear Science and Technology Organization for support during an extended research visit.
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All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials