ABSTRACT CTS-9421996 This is a study of the reactivity and dynamic behavior of adsorbates appearing during the catalytic reduction of nitric oxide, and of the interaction of silanes with alumina and with zeolites. In -situ infrared spectroscopy coupled with transient kinetic approaches are used to study site structure and dynamic behavior of various adsorbates during the reaction of nitric oxide and carbon monoxide over rhodium-based catalysts, and during the reaction of nitric oxide, methane, and oxygen over ZSM-5 containing cobalt or copper. The interactions of silanes with catalyst surfaces and reactions on silane-treated catalysts are investigated. The feasibility of using silanation to improve the resistance of catalysts to sintering is assessed. Some novel approaches to catalyst assessment and design are explored in this study. Although this effort looks at systems used in control of nitrogen oxides from both mobile and stationary sources, the results will have very broad applicability. ***