Regeneration of thermally aged Pt-Rh/CexZr1-xO2-Al2O3 model three-way catalysts by oxychlorination treatments

J. A. Anderson; R. A. Daley; S. Y. Christou; A. M. Efstathiou

doi:10.1016/j.apcatb.2005.12.007

Regeneration of thermally aged Pt-Rh/Ce_xZr_1-xO₂-Al₂O₃ model three-way catalysts by oxychlorination treatments

J. A. Anderson^*, R. A. Daley, S. Y. Christou, A. M. Efstathiou

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

56 Citations (Scopus)

Abstract

Pt-Rh/Ce_xZr_1-xO₂-Al₂O₃ with 0.6 and 1.0 wt.% noble metal loadings were prepared and characterized for their metal dispersion with respect to Ce_xZr_1-xO₂-free Pt-Rh/Al₂O₃ in fresh, thermally aged and oxychlorinated states. Thermal ageing at 973 K led to loss of metal dispersion in all cases but to negligible effect on the dispersion of the Ce_xZr_1-xO₂ component where present. Oxychlorination was able to fully recover metal dispersion in all cases but led to different effects on the redox properties of Ce_xZr_1-xO₂ which appeared to be related to the metal loadings. Despite showing improved dispersion following regeneration, higher loaded catalyst showed no improvement in light-off performance for either NO reduction or CO oxidation and showed poorer oxygen storage (OSC) ability, particularly at higher temperatures. Lower loaded catalyst showed improved dispersion, improved OSC and reduced light-off temperatures for NO reduction and CO oxidation after oxychlorination compared to that in the thermally aged state.

Original language	English
Pages (from-to)	189-200
Number of pages	12
Journal	Applied Catalysis B: Environmental
Volume	64
Issue number	3-4
DOIs	https://doi.org/10.1016/j.apcatb.2005.12.007
Publication status	Published - 2 May 2006

Keywords

Oxychlorination
Pt-Rh/CeZrO-AlO
Redispersion
Regeneration
Thermal ageing
Three-way catalysts

ASJC Scopus subject areas

Catalysis
General Environmental Science
Process Chemistry and Technology

Access to Document

10.1016/j.apcatb.2005.12.007

Cite this

@article{223ca3e3477549f49b143b569ff5afc9,

title = "Regeneration of thermally aged Pt-Rh/CexZr1-xO2-Al2O3 model three-way catalysts by oxychlorination treatments",

abstract = "Pt-Rh/CexZr1-xO2-Al2O3 with 0.6 and 1.0 wt.% noble metal loadings were prepared and characterized for their metal dispersion with respect to CexZr1-xO2-free Pt-Rh/Al2O3 in fresh, thermally aged and oxychlorinated states. Thermal ageing at 973 K led to loss of metal dispersion in all cases but to negligible effect on the dispersion of the CexZr1-xO2 component where present. Oxychlorination was able to fully recover metal dispersion in all cases but led to different effects on the redox properties of CexZr1-xO2 which appeared to be related to the metal loadings. Despite showing improved dispersion following regeneration, higher loaded catalyst showed no improvement in light-off performance for either NO reduction or CO oxidation and showed poorer oxygen storage (OSC) ability, particularly at higher temperatures. Lower loaded catalyst showed improved dispersion, improved OSC and reduced light-off temperatures for NO reduction and CO oxidation after oxychlorination compared to that in the thermally aged state.",

keywords = "Oxychlorination, Pt-Rh/CeZrO-AlO, Redispersion, Regeneration, Thermal ageing, Three-way catalysts",

author = "Anderson, {J. A.} and Daley, {R. A.} and Christou, {S. Y.} and Efstathiou, {A. M.}",

note = "Funding Information: We thank the EU for funding under the fifth Framework programme (Project GRD1-2000-25605) and other members of the REGENCATS consortium for stimulating discussions. We also thank Johnson Matthey for the loan of precious metals salts used in this study. The financial support by the Research Committee of the University of Cyprus and the Cyprus Research Promotion Foundation is greatly acknowledged. ",

year = "2006",

month = may,

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doi = "10.1016/j.apcatb.2005.12.007",

language = "English",

volume = "64",

pages = "189--200",

journal = "Applied Catalysis B: Environmental",

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T1 - Regeneration of thermally aged Pt-Rh/CexZr1-xO2-Al2O3 model three-way catalysts by oxychlorination treatments

AU - Anderson, J. A.

AU - Daley, R. A.

AU - Christou, S. Y.

AU - Efstathiou, A. M.

N1 - Funding Information: We thank the EU for funding under the fifth Framework programme (Project GRD1-2000-25605) and other members of the REGENCATS consortium for stimulating discussions. We also thank Johnson Matthey for the loan of precious metals salts used in this study. The financial support by the Research Committee of the University of Cyprus and the Cyprus Research Promotion Foundation is greatly acknowledged.

PY - 2006/5/2

Y1 - 2006/5/2

N2 - Pt-Rh/CexZr1-xO2-Al2O3 with 0.6 and 1.0 wt.% noble metal loadings were prepared and characterized for their metal dispersion with respect to CexZr1-xO2-free Pt-Rh/Al2O3 in fresh, thermally aged and oxychlorinated states. Thermal ageing at 973 K led to loss of metal dispersion in all cases but to negligible effect on the dispersion of the CexZr1-xO2 component where present. Oxychlorination was able to fully recover metal dispersion in all cases but led to different effects on the redox properties of CexZr1-xO2 which appeared to be related to the metal loadings. Despite showing improved dispersion following regeneration, higher loaded catalyst showed no improvement in light-off performance for either NO reduction or CO oxidation and showed poorer oxygen storage (OSC) ability, particularly at higher temperatures. Lower loaded catalyst showed improved dispersion, improved OSC and reduced light-off temperatures for NO reduction and CO oxidation after oxychlorination compared to that in the thermally aged state.

AB - Pt-Rh/CexZr1-xO2-Al2O3 with 0.6 and 1.0 wt.% noble metal loadings were prepared and characterized for their metal dispersion with respect to CexZr1-xO2-free Pt-Rh/Al2O3 in fresh, thermally aged and oxychlorinated states. Thermal ageing at 973 K led to loss of metal dispersion in all cases but to negligible effect on the dispersion of the CexZr1-xO2 component where present. Oxychlorination was able to fully recover metal dispersion in all cases but led to different effects on the redox properties of CexZr1-xO2 which appeared to be related to the metal loadings. Despite showing improved dispersion following regeneration, higher loaded catalyst showed no improvement in light-off performance for either NO reduction or CO oxidation and showed poorer oxygen storage (OSC) ability, particularly at higher temperatures. Lower loaded catalyst showed improved dispersion, improved OSC and reduced light-off temperatures for NO reduction and CO oxidation after oxychlorination compared to that in the thermally aged state.

KW - Oxychlorination

KW - Pt-Rh/CeZrO-AlO

KW - Redispersion

KW - Regeneration

KW - Thermal ageing

KW - Three-way catalysts

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