Repository logo

Infoscience

  • English
  • French
Log In
Logo EPFL, École polytechnique fédérale de Lausanne

Infoscience

  • English
  • French
Log In
  1. Home
  2. Academic and Research Output
  3. Journal articles
  4. Reversible Segregation of Ni in LaFe0.8Ni0.2O3 +/-delta During Coke Removal
 
research article

Reversible Segregation of Ni in LaFe0.8Ni0.2O3 +/-delta During Coke Removal

Steiger, Patrick  
•
Nachtegaal, Maarten
•
Krocher, Oliver  
Show more
October 9, 2018
Chemcatchem

The deactivation of supported nickel catalysts by coking is an important technological subject for many chemical processes, especially when high concentrations of unsaturated hydrocarbons are present in the feed gas. Here, the reversible segregation of Ni from a LaFeO3 +/-delta perovskite-type host lattice was exploited to completely recover a LaFe0.8Ni0.2O3 +/-delta catalyst after it had been deliberately subjected to severe carbon deposition during CO2 methanation in ethylene rich feed gas for several hours. Temperature programmed reduction, X-ray diffraction, electron microscopy, X-ray absorption spectroscopy and catalytic activity tests were used to follow the catalyst structure along the various steps of reduction, reaction, coking and subsequent regeneration, while Raman spectroscopy and electron microscopy were used to characterize the nature of the carbon deposits. It is shown that upon reduction Ni atoms segregate to the surface of the perovskite to form catalytic active Ni particles. Oxidation stimulates Ni atoms to readopt the coordination environment of Fe in the perovskite matrix. This property persisted after severe catalyst deactivation by filamentous, partially graphitic carbon. It is demonstrated that simple catalyst reoxidation can be applied to oxidize all carbon deposits while additionally reverting segregated Ni back into the host lattice, thus protecting Ni from particle growth and resultant long-term loss of catalyst activity over multiple regeneration cycles.

  • Details
  • Metrics
Type
research article
DOI
10.1002/cctc.201800603
Web of Science ID

WOS:000446980600035

Author(s)
Steiger, Patrick  
Nachtegaal, Maarten
Krocher, Oliver  
Ferri, Davide
Date Issued

2018-10-09

Publisher

WILEY-V C H VERLAG GMBH

Published in
Chemcatchem
Volume

10

Issue

19

Start page

4456

End page

4464

Subjects

Chemistry, Physical

•

Chemistry

•

coking

•

nickel catalyst

•

perovskite-type oxides

•

self-regeneration

•

automotive-emissions control

•

carbon-dioxide

•

perovskite catalyst

•

raman-spectroscopy

•

methanation

•

nickel

•

stability

•

oxide

•

deactivation

•

performance

Editorial or Peer reviewed

REVIEWED

Written at

EPFL

EPFL units
GR-KRO  
Available on Infoscience
December 13, 2018
Use this identifier to reference this record
https://infoscience.epfl.ch/handle/20.500.14299/152195
Logo EPFL, École polytechnique fédérale de Lausanne
  • Contact
  • infoscience@epfl.ch

  • Follow us on Facebook
  • Follow us on Instagram
  • Follow us on LinkedIn
  • Follow us on X
  • Follow us on Youtube
AccessibilityLegal noticePrivacy policyCookie settingsEnd User AgreementGet helpFeedback

Infoscience is a service managed and provided by the Library and IT Services of EPFL. © EPFL, tous droits réservés