Steric effect in O2 adsorption on Pt(553), Pt(533) surfaces

Abstract

Steric effect in O2 sticking on Pt(553) and (533) surfaces has been investigated by using a state-selected O2 beam to understand the reactivity of steps on Pt surface. The results indicate the followings. (1) O2 molecules parallel to the step are more reactive than those perpendicular to it. This tendency is larger on (533) surface. (2) O2 molecules perpendicular to the step surface are less reactive than those parallel to it. (3) No steric effect is included in O2 trapping process.