title: In situ solid-state (1)H NMR studies of hydration of the solid acid catalyst ZSM-5 in its ammonium form.
abstract: Hydration of the ammonium form of the solid acid catalyst ZSM-5 is investigated by applying a technique that has been developed recently for carrying out in situ solid-state NMR studies of adsorption processes. From (1)H MAS NMR spectra recorded as a function of time and temperature during the hydration process, insights are established on the nature of the interaction between the adsorbed water molecules and the ammonium cations in the ZSM-5 material. The change in isotropic chemical shift for the ammonium cations is consistent with the formation of N-Hcdots, three dots, centeredO hydrogen bonding with the water molecules. Studies of the adsorption of deuterated water, and dehydration of the hydrated material, are also reported.
authors.affiliation: School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT Wales, UK.
authors.forename: Mingcan
authors.initials: M
authors.lastname: Xu
authors.forename: Kenneth D M
authors.initials: KD
authors.lastname: Harris
authors.forename: John Meurig
authors.initials: JM
authors.lastname: Thomas
mesh_terms: D000143:Acids / Q000737:chemistry; D003198:Computer Simulation; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D011522:Protons; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D014867:Water / Q000032:analysis / Q000737:chemistry*; D017641:Zeolites / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D000143:Acids; D011522:Protons; D000644:Quaternary Ammonium Compounds; D014867:Water; D017641:Zeolites