Application of surface science techniques in the field of zeolitic materials

Abstract

Publisher Summary Among the various surface analysis techniques that are currently available to catalysis chemists, X-ray photoelectron spectroscopy (XPS) is certainly the one, having found the widest application in the study of zeolitic materials. Reflecting this significance, this chapter mostly dwells upon XPS and its relevance to zeolites, with some mentions of the contributions of other techniques, such as auger electron spectroscopy (AES), ion scattering spectroscopy (ISS), and secondary ion mass spectrometry (SIMS). The chapter defines XPS or electron spectroscopy for chemical analysis (ESCA) as a technique, whereby a beam of monoenergetic X-ray photons interacts, with the atoms of a solid. In this interaction, electrons are extracted from their orbitals, provided the energy of the photon is higher than the binding energy of the electron on its particular level. Emphasis is given on the elements constitutive of the zeolite lattice and on the characterization of the sites that make zeolites important catalysts. These are the Bronsted and Lewis acid sites, the Lewis base sites and the oxidoreduction sites exemplified, by the isolated tetrahedral titanium atoms, in silicalite lattices.