The Water Gas Shift (WGS) reaction (CO + H2O -> CO2 + H2) is used extensively in the conversion of fossil fuels to hydrogen. Development of new improved WGS-catalysts with increased reactivity is crucial because it would allow the WGS reaction to be carried out at lower temperatures where the equilibrium concentration of CO is lower. This is important if the produced hydrogen is to be used in a low temperature fuel cell, which is poisoned by even small amounts of CO. Iron-doped palladium-based catalysts are very interesting candidates for the WGS reaction [1] and further studies of the Pd/Fe system are therefore interesting.
In this study we synthesize different model systems of iron oxide on Pd(111) and use scanning tunneling microscopy (STM) to show that the structure of the oxides depends strongly on the preparation conditions. Furthermore we use thermal desorption spectroscopy (TDS) to study the different oxides' interaction with CO.
In addition we use STM and TDS to study iron oxide on Pt(111) and use this to identify unique properties of the FePd-based catalysts. Finally our results are compared with results from high surface area WGS experiments found in the literature.
[1] Zhao, S. and R. J. Gorte (2004). "The activity of Fe-Pd alloys for the water-gas shift reaction." Catalysis Letters 92 (1-2): 75-80.