SURFACE METHOXY GROUPS IN ZEOLITES STUDIED BY MULTINUCLEAR MAS NMR-SPECTROSCOPY

Solid-state n.m.r, spectroscopy of H-1 and C-13 nuclei has been applie d in order to study chemisorbed methyl species on zeolites with differ ent intermediate electronegativity of the framework. The secondary inf luence of the framework via the carbon atoms, which is expressed in th e H-1 MAS n.m.r. spectra, gives a similar measure of the basicity of t he zeolite as the C-13 MAS n.m.r. of methoxy groups. The basicity of t he zeolite determines the reactivity of the surface methoxy groups. (C ) Elsevier Science Inc. 1997.