Three-dimensional probing of catalyst ageing on different length scales: A case study of changes in microstructure and activity for CO oxidation of a Pt-Pd/Al2O3 catalyst
Journal article, 2017
In the present study the effects of thermal treatment on the microstructure of a Pt-Pd/Al2O3 oxidation catalyst and its activity for CO oxidation have been studied. The microstructural analysis was performed using several high-resolution electron microscopy techniques like STEM, FIB/SEM slice & view, SEM and EDX. A combination of these analysis techniques and advanced TEM specimen preparation allowed for three-dimensional probing at different length scales avoiding the random character of conventionally crushed powder specimens due to site specificity. A core-shell distribution of Pt-Pd nanoparticles within the alumina support particles, with enlarged nanoparticles (≈ 1.5 to 40 nm) being present in the shell and small nanoparticles (< 1.5 nm) in the core, was revealed in the untreated catalyst. A more uniform spatial
distribution developed during thermal treatment at 700 °C or higher with larger nanoparticles forming in the core. Accompanying measurements of the catalytic activity for CO oxidation showed the detrimental effect of sintering of the small nanoparticles on the
reaction rate and apparent activation energy of the reaction.
TEM
platinum
palladium
SEM
CO oxidation
Author
Torben Nilsson Pingel
Competence Centre for Catalysis (KCK)
Chalmers, Physics, Eva Olsson Group
Sheedeh Fouladvand
Competence Centre for Catalysis (KCK)
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Marc Heggen
Forschungszentrum Jülich (FZJ)
R. E. Dunin-Borkowski
Forschungszentrum Jülich (FZJ)
Wolfgang Jäger
Competence Centre for Catalysis (KCK)
Chalmers, Physics
Peter Westenberger
FEI
Daniel Phifer
FEI Europe B.V.
Jace McNeil
FEI
Magnus Skoglundh
Competence Centre for Catalysis (KCK)
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Henrik Grönbeck
Competence Centre for Catalysis (KCK)
Chalmers, Physics, Chemical Physics
Eva Olsson
Chalmers, Physics, Eva Olsson Group
Competence Centre for Catalysis (KCK)
ChemCatChem
1867-3880 (ISSN) 1867-3899 (eISSN)
Vol. 9 18 3544-3553Enabling Science and Technology through European Electron Microscopy (ESTEEM 2)
European Commission (FP7) (EC/FP7/312483), 2012-10-01 -- 2016-09-30.
Driving Forces
Sustainable development
Areas of Advance
Nanoscience and Nanotechnology
Transport
Energy
Materials Science
Subject Categories (SSIF 2011)
Chemical Process Engineering
Condensed Matter Physics
DOI
10.1002/cctc.201700479