Probing nanoconfined water in zeolite cages: H atom dynamics and spectroscopy

Time-resolved and CW EPR were used to study radiolytically generated H atom s in water/ice nanoclusters in NaA, NaX, NaY, and HY zeolites. H atoms dyna mic properties and spectroscopy parameters are sensitive to the structural changes of water due to the nanoconfinement. Transient H atoms in HY and Na Y zeolites segregate into two different domains: socialite and super cages. In NaX zeolite only H atoms from super cages were observed. H atoms are cr eated in both silica phase and adsorbed water by radiolytic processes. The decay of H atoms occurs predominantly via reaction with the radiation-induc ed defects in silica. (C) 2001 Published by Elsevier Science B.V.