Crystal Structure of NaY Zeolite with Adsorbed CO2 by Neutron Powder Diffraction
Winnie K. Wong-Ng, James A. Kaduk, Qingzhen Huang, Laura Espinal, Martin L. Green
The crystal structure of dehydrated NaY zeolite (Na-FAU structure type) with and without adsorbed CO2 has been determined at room temperature (RT) and at 4 K using neutron powder diffraction techniques. The CO2-containing sample was prepared at -78 °C and 0.1 MPa pCO2 (dry ice sublimation conditions). Our diffraction data provides direct evidence that adsorption of CO2 results in significant migration of the extraframework Na cations in the zeolite structure. At 4 K, 45 of the apparent 76 CO2/cell were located in two crystallographically independent sites with different bonding (terminal vs. bridging) to the Na cations (Na10) in the supercage site II. While the CO2 molecules that have a linear configuration interact with Na10 via one terminal oxygen, the bridging CO2 molecules were found to have a bent O-C-O configuration (148.3(3)), with both oxygen atoms coordinating to two symmetry-related Na10. These results will help to provide a basis for interpreting CO2 adsorption phenomena in NaY and related zeolites.
, Kaduk, J.
, Huang, Q.
, Espinal, L.
and Green, M.
Crystal Structure of NaY Zeolite with Adsorbed CO2 by Neutron Powder Diffraction, Journal of Solid State Chemistry, [online], https://doi.org/10.1016/j.micromeso.2013.01.024
(Accessed June 24, 2021)