Transient stuctures of PdO during CO oxidation over Pd(100)
Journal article, 2015

In situ high-energy surface X-ray diffraction was employed to determine the surface structure dynamics of a Pd(100) single crystal surface acting as a model catalyst to promote CO oxidation. The measurements were performed under semi-realistic conditions, i.e. 100 mbar total gas pressure and 600 K sample temperature. The surface structure was studied in detail both in a steady gas ow and in a gradually changing gas composition with a time resolution of 0.5 sec. Our results show that \sqroot-PdO(101) surface oxide forms in a close to stoichiometric O2 and CO gas mixture as the mass-spectrometry indicates a transition to a highly active state with the reaction rate limited by the CO mass transfer to the Pd(100) surface. Using a low excess of O2 in the gas stoichiometry, islands of bulk oxide grow epitaxially in the same (101) crystallographic orientation of the bulk PdO unit cell according to a Stranski-Krastanov type of growth. The morphology of the islands is analyzed quantitatively. Upon further increase of the O2 partial pressure a polycrystalline Pd oxide forms on the surface.

HESXRD

CO oxidation

SXRD

PdO

Pd

heterogeneous catalysis

islands

Author

Mikhail Shipilin

Lund University

Johan Gustafson

Lund University

Chu Zhang

Lund University

Lindsay R. Merte

Lund University

Andreas Stierle

Deutsches Elektronen-Synchrotron (DESY)

Uta Hejral

Deutsches Elektronen-Synchrotron (DESY)

Uta Ruett

Deutsches Elektronen-Synchrotron (DESY)

Olof Gutowski

Deutsches Elektronen-Synchrotron (DESY)

Magnus Skoglundh

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Competence Centre for Catalysis (KCK)

Per-Anders Carlsson

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Competence Centre for Catalysis (KCK)

Edvin Lundgren

Lund University

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Time-resolved in situ methods for design of catalytic sites within sustainable chemistry

Swedish Research Council (VR), 2013-01-01 -- 2016-12-31.

Driving Forces

Sustainable development

Areas of Advance

Nanoscience and Nanotechnology

Transport

Energy

Materials Science

Subject Categories

Physical Chemistry

Condensed Matter Physics

DOI

10.103/acs.jpcc.5b04400

More information

Latest update

10/27/2018