Infrared studies of selected reactions on oxide surfaces.

Abstract

This thesis has been concerned with some aspects of the reactions of SO$\sb2$ and H$\sb2$S over various catalysts, and it has been peripherally concerned with the use of probe molecules to study the surface structure of silica. The major experimental technique has been infrared spectroscopy, sometime supported by data obtained from Raman spectroscopy, mass spectroscopy, temperature programmed desorption and gravimetric measurements. Most of the work has been related to the Claus reaction, 2H$\sb2$S + SO$\sb2 \longrightarrow$ 2H$\sb2$O + $\sp3/\sb{\rm n}$S$\sb{\rm n}$. In Chapter 3 this reaction has been studied over Al$\sb2$O$\sb3$ catalysts, in Chapter 4 over sodium impregnated Al$\sb2$O$\sb3$ catalysts, in Chapter 5 over sodium impregnated SiO$\sb2$ catalysts, and in Chapter 6 over Y type zeolites. Chapter 7 is concerned with a study of the oxidation of SO$\sb2$ over spinel (magnesium aluminate, MgAl$\sb2$O$\sb4$) with the view of examining the suitability of this material for adsorprion of SO$\sb{\rm x}$ (SO$\sb2$ + SO$\sb3$) during the regeneration of fluidized catalytic cracking (FCC) catalysts. Chapter 8 is concerned with a study of the adsorption of NO$\sb{\rm x}$ and of NO$\sb{\rm x}$/SO$\sb2$ mixtures over Al$\sb2$O$\sb3$ and CuO/Al$\sb2$O$\sb3$ catalysts, with respect to the Selective Catalytic Reduction (SCR) of NO$\sb{\rm x}$ species. The last Chapter, 9, is related to a very different study, an IR examination of the use of antimonypentamethyl, SbMe$\sb5$, as a molecule for probing the structure and accessibility of surface silanol (SiOH) groups on silica. (Abstract shortened by UMI.)