Oxygen mobility in CeO{sub 2} and Ce{sub x}Zr({sub 1-x})O{sub 2} compounds: Study by CO transient oxidation and {sup 18}O/{sup 16}O isotopic exchange

Journal Article · Thu Dec 16 04:00:00 EST 1999 · Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical

DOI:https://doi.org/10.1021/jp991270a· OSTI ID:20013654

Madier, Y; Descorme, C; Govic, A.M. Le; Duprez, D

Cerium-zirconium mixed oxides (Ce{sub x}Zr{sub 1{minus}x}O{sub 2}), precalcined at 900 C in dry air, were supplied by Rhodia Terres Rares as monophasic solid solutions. Introduction of some zirconium atoms in the ceria lattice by isomorphous substitution clearly influences the final properties of these materials as long as the cubic structure of ceria is maintained. Modifications in oxygen storage capacity (OSC measurements), redox properties (CO TPR), and oxygen exchange processes (TPIE) were studied. Ce{sub 0.63}Zr{sub 0.37}O{sub 2} was shown to have the most promising properties with the largest OSC at 400 C and the highest reactivity in O{sub 2} exchange. All mixed oxides are able to exchange very large amounts of oxygen compared to ceria, implying the participation of bulk oxygen. Furthermore, on Ce{sub x}Zr{sub (1{minus}x)}O{sub 2} samples, oxygen is predominantly exchanged via a multiple heteroexchange mechanism involving surface dioxygen species as superoxides or peroxides.

• Research Organization: Univ. de Poitiers (FR)
• OSTI ID: 20013654
• Journal Information: Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical, Journal Name: Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical Journal Issue: 50 Vol. 103; ISSN 1089-5647; ISSN JPCBFK
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
54 ENVIRONMENTAL SCIENCES
CARBON MONOXIDE
CATALYSTS
CATALYTIC CONVERTERS
CATALYTIC EFFECTS
CERIUM OXIDES
OXIDATION
OXYGEN
REDOX POTENTIAL
ZIRCONIUM OXIDES