Low frequency infrared studies of silica at the solid-gas and solid-liquid interface

Infrared spectroscopy is the most widely used technique for studying surface reactions on silica because of the ease in detecting changes occurring in the infrared bands due to the surface hydroxyl groups. Moreover, by combining the spectral information obtained from the bands due to hydroxyl groups with data obtained from the low frequency region (< 1300 cm(-1)) a much clearer picture of the surface chemistry is obtained. However, access to the low frequency region is difficult because of the opacity of the silica. Several infrared techniques that overcome the problem of the opacity of the substrate for studying surface reactions in the low frequency region at both the solid-gas and solid-liquid interface are presented. (C) 1997 Elsevier Science B.V.