| Abstract
| - The interaction of triethoxysilane (TES) with H-ferrierite (H-FER) and its effects on acidity have beeninvestigated by infrared spectroscopy. TES adsorbs only on the external surface of H-FER and allows thealmost complete disappearance of the external silanol groups. New SiH groups are formed which appear tobe inactive in acid−base interactions. The adsorption of propionitrile, which diffuses into the zeolitic channels,provides evidence for the lack of substantial perturbation of the strongly acidic internal bridging OH groups.On the contrary, the adsorption of the hindered basic probe molecule o-toluonitrile, which cannot penetratethe FER channels, shows that not only terminal silanols but also Al3+ Lewis acid sites present on the externalsurface of H-FER almost totally disappear after TES treatment. Treatment with TES seems to allow virtuallythe total deactivation of the H-FER external surface.
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