High Activity Catalytic Redox Sites Within Zeolites

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Proposal Title: High Activity Catalytic Redox Sites within ZeolitesProposal Number: CTS-0099359Principal Investigator: Carl LundInstitution: State University of New York at BuffaloThe objective of this proposal is to determine the chemical nature of high activity redox sites on zeolite catalysts. In previous work the PI postulated the novel hypothesis that the anions, rather than the cations, were involved the redox activity. A kinetic model involving nitrate and nitrite species was proposed to explain anomalous behavior above a certain partial pressure of reactant. Specifically, it was found that the rate of decomposition of nitrous oxide over a zeolite catalyst jumped to a higher level when its partial pressure exceeded a critical value. Because this phenomenon only occurred when the zeolite had been ion-exchange with iron, there is some interaction with the cation. The proposed research may reveal a new type of redox chemistry, which may be applied to the decomposition of NOx compounds as well as partial oxidation reactions. The use of gravimetry, infrared spectroscopy, microcalorimetry, isotope-labeling studies, and detailed kinetic studies may reveal the nature and identity of the high activity redox sites. This work has the potential to elucidate phenomena important in industrial and environmental applications including the selective catalytic reduction of nitrogen oxides.