Faceting of Rhodium(553) in Realistic Reaction Mixtures of Carbon Monoxide and Oxygen
Journal article, 2015
We have investigated the gas composition-dependent faceting of a Rh(553) surface during catalytic CO oxidation under semirealistic reaction conditions using Surface X- ray Diffraction. We find that under stoichiometric CO and O2 conditions, the Rh(553) surface maintains its surface orientation without facet formation. In oxygen excess, the CO oxidation reaction becomes mass transfer limited by the CO diffusion, and the sur- face is observed to expose (331) or (11 ̄1) facets in coexistence with larger (111) terraces. The observed facet formation has previously been observed for pure O2 exposures of the Rh(553) surface, but at significantly lower O2 partial pressures. Surprisingly, in CO excess, which results in a CO poisoned surface with low activity, we instead find coexisting (110) and (111) facets. The reasons for and possible implications of the observed facetings are discussed.
CO oxidation
vicinal surface
Surface X-ray diffraction
Author
Chu Zhang
Lunds Universitet
Edvin Lundgren
Lunds Universitet
Per-Anders Carlsson
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Competence Centre for Catalysis (KCK)
Olivier Balmes
Lunds Universitet
Anders Hellman
Competence Centre for Catalysis (KCK)
Lindsay R. Merte
Lunds Universitet
Mikhail Shipilin
Lunds Universitet
Willem Onderwaater
Leiden University
European Synchrotron Radiation Facility
Johan Gustafson
Lunds Universitet
Journal of Physical Chemistry C
1932-7447 (ISSN) 1932-7455 (eISSN)
Vol. 119 21 11646-11652Driving Forces
Sustainable development
Areas of Advance
Nanoscience and Nanotechnology
Transport
Energy
Materials Science
Subject Categories (SSIF 2011)
Physical Chemistry
Condensed Matter Physics
DOI
10.1021/acs.jpcc.5b01841