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Structural Characterization of Ceria–zirconia Powder Catalysts Prepared by High-energy Mechanical Milling: A Neutron Diffraction Study

Published online by Cambridge University Press:  31 January 2011

S. Enzo
Affiliation:
Istituto Nazionale di Fisica per la Materia e Dipartimento di Chimica dell'Universitàdi Sassari, via Vienna 2, 07100 Sassari, Italy
F. Delogu
Affiliation:
Istituto Nazionale di Fisica per la Materia e Dipartimento di Chimica dell'Universitàdi Sassari, via Vienna 2, 07100 Sassari, Italy
R. Frattini
Affiliation:
Istituto Nazionale di Fisica della Materia e Dipartimento di Chimica Fisica dell'Universitàdi Venezia, Dorsoduro 2137, 30123 Venezia, Italy
A. Primavera
Affiliation:
Dipartimento di Scienze e Tecnologie Chimiche, Universitàdi Udine, via Cotonifico 108, 33100 Udine, Italy
A. Trovarelli
Affiliation:
Dipartimento di Scienze e Tecnologie Chimiche, Universitàdi Udine, via Cotonifico 108, 33100 Udine, Italy
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Abstract

Neutron diffraction measurements were carried out on samples of CeO2–ZrO2 powder catalysts prepared by high-energy mechanical milling. The formation of solid solution was evidenced across the entire composition range examined. Quantitative phase evaluation by the Rietveld method indicated formation of tetragonal structure for low CeO2 content, whereas cubic solid solutions were the stable form at high CeO2 loading. In addition, a pseudocubic or tetragonal t″ cell with axial ratio of unity and with internal deformation of the oxygen sublattice was observed at intermediate composition (50 mol% CeO2). Thermal annealing up to 1000 °C showed expansion of the unit cell parameters; an increase in the degree of tetragonality at the expense of cubic and monoclinic phase was observed for composition CexZr1−xO2 (x < 0.5).

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Articles
Copyright
Copyright © Materials Research Society 2000

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