Correlation between deuterium NMR spectral components and MCM-41 pore surface hydration sites

The elucidation of water molecule dynamics on surfaces and in confined geometry using NMR techniques is facilitated by knowledge about the different hydration sites involved and about the correlation between NMR spectral features and such sites. In the mesoporous molecular sieve MCM-41 substantial information exists about the former, however, satisfactory information about the latter is still lacking for this material. In the present investigation proton and deuteron NMR, MAS, and CPMAS techniques are used to establish a definitive assignment of deuterium spectral features to water at single and hydrogen-bonded pore surface hydroxyl group binding sites in MCM-41.