The interaction of CO with ceria under conditions typically used to measure the oxygen storage capacity (OSC) of automotive three way catalysts (TWC) has been investigated by in situ Raman spectroscopy. During exposure of the ceria to CO at 623 K vibrational bands at 1582-1600 and 1331-1340 cm )1 appeared; these bands increased with increasing time of exposure to CO. The band positions are consistent with phonon modes of carbon; however, assignment to carboxylate species or carbonate species cannot be excluded. Subsequent exposure to O 2 at room temperature resulted in a decrease in the intensities of the 1582-1600 and 1331-1340 cm )1 bands by more than 90%. As well, exposure to O 2 at room temperature also resulted in the appearance of Raman modes characteristic of formate and peroxide surface species. The mechanism by which formate forms upon room temperature O 2 exposure is discussed in the context of the assignment of the 1582-1600 and 1331-1340 cm )1 bands to carbon phonon modes which result from the disproportionation of CO on reduced ceria.

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Public Reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. AMBIENT REACTIVE SORPTION OF CW SIMULANTS ON CATION EXCHANGED ZEOLITES FUNDING NUMBERS DAAD19-01-1-0620 AUTHOR(S)Howard Greene, Philip Morrison, Meghan Swanson PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)Case Western Zeolite sorbent/catalyst materials were prepared, characterized and then utilized to determine their surface interactions at ambient temperature with common CW simulants for VX and HD. From this research, new insights regarding reactive sorption pathways of simulants on exchanged zeolites at ambient temperature have been proposed which will aid in developing superior alternates for sorption and detoxification of CW agents in the field. Experiments utilized a Bomem FTIR spectrometer with Harrick cell for in situ measurements of interactions between zeolite and CW simulant. Zeolite Si/Al ratios were varied from 15 to 40. Three sorbent /catalyst media were evaluated (Chromium-ZSM-5, Silver-ZSM-5 and standard gamma alumina). Results showed maximum destruction of TCE and DEMP simulants by Chromium-ZSM-5, followed by Silver-ZSM-5. Gamma alumina was found to be the least destructive. Initial work with dichloropropene (DCP), which is a common pesticide and also a CW simulant showed ambient chemisorption and also chemical rearrangement on Chromium-ZSM-5.