Significant enhancement of the oxidation of CO by H2 and/or H2O on a FeOx/Pt/TiO2 catalyst

Oxidation of CO on the FeO (x) /Pt/TiO2 catalyst is markedly enhanced by H-2 and/or H2O at 60 degrees C, but no such enhancement is observed on the Pt/TiO2 catalyst, but shift reaction (CO + H2O --> H-2 + CO2) does not occur on the FeO (x) /Pt/TiO2 catalyst at 60 degrees C. DRIFT-IR spectroscopy reveals that the fraction of bridge bonded CO increases while that of linearly bonded CO decreases on the FeO (x) loaded Pt/TiO2 catalyst. The in-situ DRIFT IR spectra proved that the bridged CO is more reactive than the linearly bonded CO with respect to O-2, and the reaction of the bridge-bonded CO with O-2 as well as of the linearly bonded CO is markedly enhanced by adding H-2 to a flow of CO + O-2. From these results, we deduced that the promoting effect of H-2 and/or H2O is responsible for the preferential oxidation (PROX) reaction of CO on the FeO (x) /Pt/TiO2 catalyst, and a following new mechanism via the hydroxyl carbonyl or bicarbonate intermediate is proposed for the oxidation of CO in the presence of H2O. [GRAPHICS]