Acidity and Mechanism in Reactions Catalyzed By Strong Acid Catalyst, Solid and Liquid

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The objective of this proposal is to develop consistent methods for determining the acidity functions of solid acid catalysts. Three components are proposed: evaluation of Lewis acidity by complexation of linear ethers, examination of Bronsted sites by adsorption of pyridine derivatives, and exploration of reaction mechanisms associated with conversation of saturated hydrocarbons. One aspect will be the development of a quantitative scale for Lewis acidity using ethers as bases and nuclear magnetic resonance as the probe. The dependence of acid strength on local curvature has been observed and will be investigated. In addition to a calibration of acid strength from equilibrium measurements as higher temperatures, reactions of hydrocarbons on zeolites at lower temperatures, where thermal activation is less important, will be studied. The reactants chosen, paraffins and cycloparaffins, are those that require the greatest strength of catalyst for an acid-catalyzed reaction. This work will help provide a clearer, fundamental understanding of some newer-generation solid acids such as zirconia-supported sulfates and heteropolyacids.