Mechanistic Study of Methanol Interaction with IB Metals (Cu and Au) Doped Ceria

Wednesday, November 10, 2010: 1:45 PM
151 F Room (Salt Palace Convention Center)
Nan Yi, Rui Si, Howard Saltsburg and Maria Flytzani-Stephanopoulos, Department of Chemical and Biological Engineering, Tufts University, Medford, MA

Clean and efficient hydrogen production is of interest because of the potential of hydrogen to be the energy carrier of the future. In order to harness chemical energy from methanol into a practical and industry-usable form, investigations to elucidate the mechanism of methanol decomposition are needed. Here we investigated the methanol interaction with IB metals (Cu and Au) prepared as clusters on nanoscale ceria by a combination of temperature-programmed techniques along with catalytic activity tests. Cu-ceria and Au-ceria were prepared by the Urea-gelation Coprecipitation (UGC) and Deposition-Precipitation (DP) methods, respectively. Cu-, Au- ceria were exposed to the various components (CH3OH, HCOOH, HCOOCH3, CO2 and H2), that are reactants, intermediates, or products in the methanol decomposition reaction. TPD and TPSR results identified the existence of methyl formate over the IB metals, which, in turn controls the selectivity to carbon products (CO, CO2 and CH4). Methyl formate was also found on Cu-ceria and Au-ceria prepared by other methods and with different metals loading, which indicated the formation of methyl formate is unique for IB metals. Moreover, activity results showed that methyl formate and hydrogen are the dominant products below 250 oC. The presentation will include data on the stability with time-on-stream and start-up/shut-down stability tests to discuss the suitability of these catalysts for fuel cell applications.

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