Steps on Pt stereodynamically filter sticking of O2

Title	Steps on Pt stereodynamically filter sticking of O2
Authors	Kun Cao, Richard van Lent, Aart W. Kleyn, Mitsunori Kurahashi, Ludo B. F. Juurlink
Magazine	Proceedings of the National Academy of Sciences of the United States of America
Date	05/29/2019
DOI	10.1073/pnas.1902846116
Introduction	Low coordinated sites on catalytic surfaces often significantly improve reactivity, yet the precise dynamical processes involved are not well comprehended. By employing two separate methodologies, this study delves into the reactivity of O2 as it encounters platinum surfaces, elucidating how step edges on (111) terraces amplify the sticking process. At lower incident energies, the linear relationship with step density, along with independence from step type and insensitivity to the molecular alignment of O2, indicates that a physisorbed state is formed before molecular chemisorption and dissociation take place. Conversely, at elevated impact energies, molecular chemisorption can occur directly on both steps and terraces simultaneously. While terraces exhibit indifference to the molecule's alignment within the (111) plane, steps show a preference for molecules impacting with their internuclear axis aligned parallel to the edge. Thus, stereodynamical filtering is pivotal in controlling the sticking and dissociation of O2 on Pt, with steps playing a dual role.
Quote	Kun Cao, Richard van Lent and Aart W. Kleyn et al. Steps on Pt stereodynamically filter sticking of O2. Proceedings of the National Academy of Sciences of the United States of America. 2019. Vol. 116(28):13862-13866. DOI: 10.1073/pnas.1902846116
Element	Oxygen (O) , Platinum (Pt)