A model Pd/Fe2O3 catalyst prepared by the vacuum technique has been studied
in the carbon monoxide oxidation in the temperature range of 300-550 K at
reagent pressures P(CO)= 16 Torr, P(O-2)= 4 Torr. It has been shown that th
e activity of the fresh catalysts is determined by palladium. According to
the XPS data, the reduction with carbon monoxide results in the formation o
f Fe2+ (formally Fe3O (4)) and appearance of the catalytic activity in this
reaction at low temperatures (350 K). High low-temperature activity of the
catalyst is supposed to be connected with the reaction between oxygen adso
rbed on the reduced sites of the support (Fe2+) and CO adsorbed on palladiu
m (COads) at the metal-oxide interface.