Morphology of Rhodium Particles in Ex-chloride Rh/Ce0.5Zr0.5O2 Catalyst

G. Vlaic; P. Fornasiero; G. Martra; E. Fonda; J. Kašpar; L. Marchese; E. Tomat; S. Coluccia; M. Graziani

doi:10.1006/jcat.1999.2731

Morphology of Rhodium Particles in Ex-chloride Rh/Ce_0.5Zr_0.5O₂ Catalyst

G. Vlaic, P. Fornasiero, G. Martra, E. Fonda, J. Kašpar, L. Marchese, E. Tomat, S. Coluccia, M. Graziani

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

19 Scopus citations

Abstract

The morphology of rhodium particles in a 5 wt% Rh/Ce_0.5Zr_0.5O₂ catalyst subjected to different treatments is investigated by EXAFS, HREM, and H₂ chemisorption. Despite the high Rh loading, highly dispersed metal particles are observed in the sample. In the presence of NO and CO, the Rh particles are easily oxidized to give small Rh oxide clusters, and the high rhodium dispersion is retained even after a further reduction at 773 K. Comparison with an Rh/Al₂O₃ prepared under identical conditions clearly suggests that the presence of the Ce_0.5Zr_0.5O₂ support favors high dispersion of rhodium particles. Despite the fact that RhCl₃·nH₂O has been employed as precursor, no chloride could be detected in the Rh nearest-neighbor shell, suggesting its migration over the support.

Original language	English (US)
Pages (from-to)	182-190
Number of pages	9
Journal	Journal of Catalysis
Volume	190
Issue number	1
DOIs	https://doi.org/10.1006/jcat.1999.2731
State	Published - Feb 15 2000
Externally published	Yes

Keywords

Ceria-zirconia mixed oxides
EXAFS analysis of
Rh catalysts
Rh/CeO-ZrO solid solutions
Rhodium catalysts
Rhodium chloride
Three-way catalysts

ASJC Scopus subject areas

Catalysis
Physical and Theoretical Chemistry

Access to Document

10.1006/jcat.1999.2731

Cite this

@article{158988d4ed954b38bcd190bec84bc98c,

title = "Morphology of Rhodium Particles in Ex-chloride Rh/Ce0.5Zr0.5O2 Catalyst",

abstract = "The morphology of rhodium particles in a 5 wt% Rh/Ce0.5Zr0.5O2 catalyst subjected to different treatments is investigated by EXAFS, HREM, and H2 chemisorption. Despite the high Rh loading, highly dispersed metal particles are observed in the sample. In the presence of NO and CO, the Rh particles are easily oxidized to give small Rh oxide clusters, and the high rhodium dispersion is retained even after a further reduction at 773 K. Comparison with an Rh/Al2O3 prepared under identical conditions clearly suggests that the presence of the Ce0.5Zr0.5O2 support favors high dispersion of rhodium particles. Despite the fact that RhCl3·nH2O has been employed as precursor, no chloride could be detected in the Rh nearest-neighbor shell, suggesting its migration over the support.",

keywords = "Ceria-zirconia mixed oxides, EXAFS analysis of, Rh catalysts, Rh/CeO-ZrO solid solutions, Rhodium catalysts, Rhodium chloride, Three-way catalysts",

author = "G. Vlaic and P. Fornasiero and G. Martra and E. Fonda and J. Ka{\v s}par and L. Marchese and E. Tomat and S. Coluccia and M. Graziani",

note = "Funding Information: Mr. Elvio Merlach and Mr. Renzo Crevatin, Dipartimento di Scienze Chimiche, Universit{\`a} di Trieste, are gratefully acknowledged for the design and manufacture of the in situ EXAFS cell. The University of Trieste, the Ministero dell{\textquoteright}Ambiente (Roma), Contract DG 164/SCOC/97, CNR (Roma) Programmi Finalizzati “Materiali Speciali per Tecnologie Avan-zate II, Contract 97.00896.34, and MURST (Roma) “Progetti di Ricerca di Rilevante Interesse Nazionale—1998” are gratefully acknowledged for financial support. The technical assistance of the staff at LURE is gratefully acknowledged.",

year = "2000",

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doi = "10.1006/jcat.1999.2731",

language = "English (US)",

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T1 - Morphology of Rhodium Particles in Ex-chloride Rh/Ce0.5Zr0.5O2 Catalyst

AU - Vlaic, G.

AU - Fornasiero, P.

AU - Martra, G.

AU - Fonda, E.

AU - Kašpar, J.

AU - Marchese, L.

AU - Tomat, E.

AU - Coluccia, S.

AU - Graziani, M.

N1 - Funding Information: Mr. Elvio Merlach and Mr. Renzo Crevatin, Dipartimento di Scienze Chimiche, Università di Trieste, are gratefully acknowledged for the design and manufacture of the in situ EXAFS cell. The University of Trieste, the Ministero dell’Ambiente (Roma), Contract DG 164/SCOC/97, CNR (Roma) Programmi Finalizzati “Materiali Speciali per Tecnologie Avan-zate II, Contract 97.00896.34, and MURST (Roma) “Progetti di Ricerca di Rilevante Interesse Nazionale—1998” are gratefully acknowledged for financial support. The technical assistance of the staff at LURE is gratefully acknowledged.

PY - 2000/2/15

Y1 - 2000/2/15

N2 - The morphology of rhodium particles in a 5 wt% Rh/Ce0.5Zr0.5O2 catalyst subjected to different treatments is investigated by EXAFS, HREM, and H2 chemisorption. Despite the high Rh loading, highly dispersed metal particles are observed in the sample. In the presence of NO and CO, the Rh particles are easily oxidized to give small Rh oxide clusters, and the high rhodium dispersion is retained even after a further reduction at 773 K. Comparison with an Rh/Al2O3 prepared under identical conditions clearly suggests that the presence of the Ce0.5Zr0.5O2 support favors high dispersion of rhodium particles. Despite the fact that RhCl3·nH2O has been employed as precursor, no chloride could be detected in the Rh nearest-neighbor shell, suggesting its migration over the support.

AB - The morphology of rhodium particles in a 5 wt% Rh/Ce0.5Zr0.5O2 catalyst subjected to different treatments is investigated by EXAFS, HREM, and H2 chemisorption. Despite the high Rh loading, highly dispersed metal particles are observed in the sample. In the presence of NO and CO, the Rh particles are easily oxidized to give small Rh oxide clusters, and the high rhodium dispersion is retained even after a further reduction at 773 K. Comparison with an Rh/Al2O3 prepared under identical conditions clearly suggests that the presence of the Ce0.5Zr0.5O2 support favors high dispersion of rhodium particles. Despite the fact that RhCl3·nH2O has been employed as precursor, no chloride could be detected in the Rh nearest-neighbor shell, suggesting its migration over the support.

KW - Ceria-zirconia mixed oxides

KW - EXAFS analysis of

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KW - Rh/CeO-ZrO solid solutions

KW - Rhodium catalysts

KW - Rhodium chloride

KW - Three-way catalysts

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