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.

platinum

CO oxidation

TEM

SEM

palladium

Author

Torben Pingel

Chalmers, Physics, Eva Olsson Group

Competence Centre for Catalysis (KCK)

Sheedeh Fouladvand

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

Competence Centre for Catalysis (KCK)

Marc Heggen

Forschungszentrum Jülich

R. E. Dunin-Borkowski

Forschungszentrum Jülich

Wolfgang Jäger

Competence Centre for Catalysis (KCK)

Chalmers, Physics

Peter Westenberger

FEI Company

Daniel Phifer

FEI Company

Jace McNeil

FEI Company

Magnus Skoglundh

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

Competence Centre for Catalysis (KCK)

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 3544-3553

Enabling Science and Technology through European Electron Microscopy (ESTEEM 2)

European Commission (FP7), 2012-10-01 -- 2016-09-30.

Driving Forces

Sustainable development

Areas of Advance

Nanoscience and Nanotechnology

Transport

Energy

Materials Science

Subject Categories

Chemical Process Engineering

Condensed Matter Physics

DOI

10.1002/cctc.201700479

More information

Latest update

11/5/2018