Synthesis and Characterization of Solid Acids

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This award is made to Dr. Russell S. Drago of the Chemistry Department, University of Florida, for investigation of a new method to measure and control the acidity of solid acid catalysts. The award is in the Technology for Sustainable Environment component of the EPA/NSF Partnership for Environmental Research, and support is provided by the Inorganic, Bioinorganic, and Organometallic Chemistry Program and the Office of Multidisciplinary Activities. Solid acid catalysts substituted for strong acid solvents and reagents can reduce toxic wastes associated with many industrial processes, such as alkylation, that require sulfuric acid or hydrofluoric acid to promote reaction. Results of calorimetric titrations and adsorption isotherms will be used to determine equilibrium constants and enthalpies for various reaction sites on the solids. When coupled with spectroscopic and reactivity data, reaction thresholds and optimum solid acidities will be determined for reactions of interest. Sol-gel methods will be used to prepare a series of solid acids that incorporate different high oxidation state elements into the silica structure. The effect of element changes and systematic changes in the synthesis variables on acidity will be determined and correlated with selectivity of various solid acid catalysts for isomerization of alkanes. Non-porous and microporous solids with similar acid strengths will be compared. The petroleum industry uses hydrofluoric and sulfuric acids to initiate many reactions that alter the arrangement or length of molecular carbon chains. Solid acids that can replace these aqueous acids provide inexpensive and reusable substitutes in many areas of refining. In this study, a systematic approach to assessing the effectiveness of solid acids in various reactions will be developed.