Partial encapsulation of Pd particles by reduced ceria-zirconia

Journal Article · Mon Nov 14 00:00:00 EST 2005 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.2132067· OSTI ID:876860

Sun, H P; Pan, X Q; Graham, George W; Jen, H W; McCabe, Robert W; Thevuthasan, Suntharampillai; Peden, Charles HF

The interaction between metal particles and their oxide support can be strong so as to affect the reactivity of a catalyst system by, for example, encapsulation of the particles by the oxide. Direct observation of metal-oxide interfaces with atomic resolution is a challenge and can only be achieved by cross sectional high-resolution transmission electron microscopy (HRTEM). With this approach, we found partial encapsulation of Pd particles by reduced ceria-zirconia in a model, single-crystal thin film auto catalyst, indicating a strong interaction between Pd and the oxide. Besides obtaining HRTEM images, the valence of cerium was determined by electron energy loss spectroscopy (EELS). The effect of reduction and oxidation conditions on this interaction provides a qualitative explanation for a previously observed reversible reactivation of oxygen storage in model powder auto catalysts. The technique of cross sectional HRTEM can be applied to the study of other metal-particle-on-oxide systems.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 876860
• Report Number(s): PNNL-SA-38573; APPLAB; 1805; KC0302010; TRN: US0601566
• Journal Information: Applied Physics Letters, Vol. 87, Issue 20; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CATALYSTS
CERIUM
ELECTRONS
ENCAPSULATION
ENERGY-LOSS SPECTROSCOPY
OXIDATION
OXIDES
OXYGEN
RESOLUTION
STORAGE
STRONG INTERACTIONS
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
VALENCE
strong metal suport interaction
ceria-zirconia
Palladium
catalytic converters
oxygen storage materials
Environmental Molecular Sciences Laboratory