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Scaling Platinum-Catalyzed Hydrogen Dissociation on Corrugated Surfaces |
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| Authors: | Sabine V Auras Dr Richard van Lent Dr Dima Bashlakov Jessika M Piñeiros Bastidas Tycho Roorda Rick Spierenburg Assoc Prof Ludo B F Juurlink |
| Institution: | 1. Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands;2. ILTPE, National Academy of Sciences of Ukraine, 47 Nauky Ave., Kharkiv, 61103 Ukraine;3. Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands
These authors contributed equally to this work. |
| Abstract: | We determine absolute reactivities for dissociation at low coordinated Pt sites. Two curved Pt(111) single-crystal surfaces allow us to probe either straight or highly kinked step edges with molecules impinging at a low impact energy. A model extracts the average reactivity of inner and outer kink atoms, which is compared to the reactivity of straight A- and B-type steps. Local surface coordination numbers do not adequately capture reactivity trends for H2 dissociation. We utilize the increase of reactivity with step density to determine the area over which a step causes increased dissociation. This step-type specific reactive area extends beyond the step edge onto the (111) terrace. It defines the reaction cross-section for H2 dissociation at the step, bypassing assumptions about contributions of individual types of surface atoms. Our results stress the non-local nature of H2 interaction with a surface and provide insight into reactivity differences for nearly identical step sites. |
| Keywords: | corrugated surfaces heterogeneous catalysis reaction cross-sections reaction mechanisms surface chemistry |