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
Artikel i vetenskaplig tidskrift, 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

SEM

CO oxidation

palladium

platinum

Författare

Torben Nilsson Pingel

Kompetenscentrum katalys (KCK)

Chalmers, Fysik, Eva Olsson Group

Sheedeh Fouladvand

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Kompetenscentrum katalys (KCK)

Marc Heggen

Forschungszentrum Jülich

R. E. Dunin-Borkowski

Forschungszentrum Jülich

Wolfgang Jäger

Kompetenscentrum katalys (KCK)

Chalmers, Fysik

Peter Westenberger

FEI Company

Daniel Phifer

FEI Company

Jace McNeil

FEI Company

Magnus Skoglundh

Kompetenscentrum katalys (KCK)

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Henrik Grönbeck

Chalmers, Fysik, Kemisk fysik

Kompetenscentrum katalys (KCK)

Eva Olsson

Kompetenscentrum katalys (KCK)

Chalmers, Fysik, Eva Olsson Group

ChemCatChem

1867-3880 (ISSN) 1867-3899 (eISSN)

Vol. 9 18 3544-3553

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

Europeiska kommissionen (FP7), 2012-10-01 -- 2016-09-30.

Drivkrafter

Hållbar utveckling

Styrkeområden

Nanovetenskap och nanoteknik

Transport

Energi

Materialvetenskap

Ämneskategorier

Kemiska processer

Den kondenserade materiens fysik

DOI

10.1002/cctc.201700479