抄録
In this study, we aimed at measuring the quantitative reactivity of O2 and H2O with Ce films with clean surface at 298K. In Ce-O2 system, the reactivity of O2 with the Ce surface exhibited the highest value at the initial stage, meaning that all O2 molecules impinging the surface can adsorb on the Ce surface. With the increasing amount of adsorbed O2, the O2 reactivity decreased rapidly. Ce was found to have higher O2 reactivity compared with other rare earths metals. In Ce-H2O system, the reactivity of H2O with the Ce surface exhibited also the highest value at the initial stage, suggesting that all H2O molecules impinging the surface adsorb and dissociate into H, O and/or OH. The number of the H atoms dissociated from the adsorbed H2O molecules was found to decrease with the increasing amount of adsorbed H2O molecules. A quantitative analysis was made for the reactivity of the H atoms dissociated from H2O.
