A new catalyst for selective oxidation of CO in H2:: Part 1, activation by depositing a large amount of FeOx on Pt/Al2O3 and Pt/CeO2 catalysts

1% Pt/Al2O3 and 1% Pt/CeO2 are markedly activated by the deposition of a large quantity of FeOx, about 100 wt% in Fe with respect to the supports. In contrast, the activity of a Ru/Al2O3 catalyst was completely suppressed by the deposition of FeOx, but a Ru-Pt/Al2O3 was markedly activated by the FeOx. The activation depends on the sequence of the deposition, that is, no pronounced activation was observed on the Pt supported on a FeOx/Al2O3 as well as on the Pt codeposited with a small amount of Fe on Al2O3, that is, the activity was almost equal to that of the Pt/Al2O3. The XPS analysis of the Pt/CeO2 and FeOx/Pt/CeO2 proved that the Pt is effectively covered with the FeOx. Selectivity for the oxidation of CO in H-2 was also improved on the FeOx/Pt/Al2O3 and FeOx/Pt/CeO2 catalysts and it is rather independent of the conversion. In conformity with the feature of the FeOx/Pt/Al2O3 and FeOx/Pt/CeO2 catalysts, we deduced that the deposited FeOx is activated by the Pt and the FeOx is responsible for the selective oxidation of CO.