Probing zeolites by vibrational spectroscopies

This review faces the most relevant aspects of vibrational spectroscopies (IR, Raman and INS) applied to zeolites and zeotype materials. Surface Brønsted and Lewis acidity and surface basicity are treated in detail. The role of probe molecules and the relevance to tune both the proton affinity and the steric hindrance of the probe to fully understand and map the complex site population present inside microporous materials is critically discussed. A detailed description of the methods needed to precisely determine the IR adsorption coefficients is given allowing to make IR a quantitative technique. The thermodynamic parameters of the adsorption process that can be extracted from a variable temperature IR study are described. Finally, cutting edge space and time resolved experiments are reviewed. All aspects are discussed by reporting relevant examples. When available, the theoretical literature related to the reviewed experimental results is reported in order to support the interpretation of the vibrational spectra on an atomistic level.