Structure and Chemistry of Flat and Stepped Rh Surfaces during NO Dissociation near 1 mbar
Journal article, 2026
The dissociation of NO is a critical step in its catalytic reduction to N2, which is key to automotive exhaust treatment. Here, we examine the role of Rh atomic steps in the NO dissociation reaction under 0.05 mbar NO. We use a Rh crystal sample curved around the (111) direction and ambient-pressure X-ray photoelectron spectroscopy to probe different Rh surfaces subject to the very same reaction conditions. At the dissociation onset, this approach allows us to quantitatively determine the NO species involved in the reaction, and to rationally assess the process in terms of diffusion and dissociation probability at terraces and steps. At a higher temperature we trigger surface oxidation, which begins preferentially on flat Rh(111) and B-type stepped surfaces, as compared to A-type stepped surfaces. Surface X-ray diffraction performed on single crystal samples reveals similar oxide structures at the atomic scale, but while B-type Rh(553) and Rh(111) surfaces do not reconstruct, A-type Rh(223) facet exhibits faceting. These findings underscore the structural sensitivity of NO dissociation and its potential impact on Rh-catalyzed NO reduction.
Author
Fernando Garcia-Martinez
University of the Basque Country (UPV/EHU)
Deutsches Elektronen-Synchrotron (DESY)
Hanna Sjo
Lund University
Khadiza Ali
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Lisa Ramisch
Lund University
Harald Wallander
Lund University
Malmö university
Lindsay R. Merte
Malmö university
Lund University
Zoltan Hegedus
Deutsches Elektronen-Synchrotron (DESY)
Johan Zetterberg
Lund University
Edvin Lundgren
Lund University
Frederik Schiller
University of the Basque Country (UPV/EHU)
Johan Gustafson
Lund University
J. Enrique Ortega
University of the Basque Country (UPV/EHU)
Journal of the American Chemical Society
0002-7863 (ISSN) 1520-5126 (eISSN)
Vol. 148 14824-14834Kähler-Einstein metrics, random point processes and variational principles (RANDOM-KAHLER)
European Commission (EC), 2013-01-01 -- 2017-12-31.
European Commission (EC), 2013-01-01 -- 2017-12-31.
Atomistic Design of Catalysts
Knut and Alice Wallenberg Foundation (KAW2015.0058), 2016-01-07 -- 2021-06-30.
Subject Categories (SSIF 2025)
Atom and Molecular Physics and Optics
Inorganic Chemistry
Physical Chemistry
DOI
10.1021/jacs.5c18969
PubMed
41926652