Site-specific reactivity of molecules with surface defects-the case of H2 dissociation on Pt

Richard van Lent; Sabine V Auras; Kun Cao; Anton J Walsh; Michael A Gleeson; Ludo B F Juurlink

doi:10.1126/science.aau6716

Site-specific reactivity of molecules with surface defects-the case of H₂ dissociation on Pt

Science. 2019 Jan 11;363(6423):155-157. doi: 10.1126/science.aau6716.

Authors

Richard van Lent^{1

2}, Sabine V Auras¹, Kun Cao¹, Anton J Walsh², Michael A Gleeson², Ludo B F Juurlink³

Affiliations

¹ Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, Netherlands.
² Dutch Institute for Fundamental Energy Research, de Zaale 20, Eindhoven 5612 AJ, Netherlands.
³ Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, Netherlands. l.juurlink@chem.leidenuniv.nl.

PMID: 30630927
DOI: 10.1126/science.aau6716

Abstract

The classic system that describes weakly activated dissociation in heterogeneous catalysis has been explained by two dynamical models that are fundamentally at odds. Whereas one model for hydrogen dissociation on platinum(111) invokes a preequilibrium and diffusion toward defects, the other is based on direct and local reaction. We resolve this dispute by quantifying site-specific reactivity using a curved platinum single-crystal surface. Reactivity is step-type dependent and varies linearly with step density. Only the model that relies on localized dissociation is consistent with our results. Our approach provides absolute, site-specific reaction cross sections.