Steps on Pt stereodynamically filter sticking of O 2

Significance Platinum is widely applied as an oxidation catalyst. The surfaces of metallic catalyst particles are generally composed of atomically flat planes connected by edges. In this paper, we unveil how Pt edges affect O 2 sticking. Opposing types of behaviors are observed for high and low incident energies. The dependencies identify the mechanisms by which O 2 molecules stick, which is the first step in the oxidation reactions.