DOI

Here, we report the results of our 1H nuclear magnetic resonance study of the dynamics of water molecules confined in zeolites (mordenite and ZSM-5 structures) with hierarchical porosity (micropores in zeolite lamella and mesopores formed by amorphous SiO 2 in the inter-lamellar space). 1H nuclear magnetic resonance (NMR) spectra show that water experiences complex behavior within the temperature range from 173 to 298 K. The temperature dependence of 1H spin-lattice relaxation evidences the presence of three processes with different activation energies: freezing (about 30 kJ/mol), fast rotation (about 10 kJ/mol), and translational motion of water molecules (23.6 and 26.0 kJ/mol for pillared mordenite and ZSM-5, respectively). For translational motion, the activation energy is markedly lower than for water in mesoporous silica or zeolites with similar mesopore size but with disordered secondary porosity. This indicates that the process of water diffusion in zeolites with hierarchical porosity is governed not only by the presence of mesopores, but also by the mutual arrangement of meso- and micropores. The translational motion of water molecules is determined mainly by zeolite micropores.

Translated title of the contributionНаноконформированная вода в пилларированных цеолитах по данным 1Н ядерного магнитного резонанса
Original languageEnglish
Article number15898
Number of pages20
JournalInternational Journal of Molecular Sciences
Volume24
Issue number21
DOIs
StatePublished - 2 Nov 2023

    Research areas

  • Zeolites/chemistry, Silicon Dioxide/chemistry, Water/chemistry, Magnetic Resonance Spectroscopy/methods, hierarchical zeolites, ZSM-5, water dynamics, mordenite, proton NMR

    Scopus subject areas

  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Inorganic Chemistry

ID: 113795423