Characterization of copper cobalt mixed oxide

Journal Article · Thu Nov 01 04:00:00 EST 1990 · Journal of Solid State Chemistry; (USA)

DOI:https://doi.org/10.1016/0022-4596(90)90308-K· OSTI ID:6067368

Li, Guohui; Dai, Lizhen; Lu, Dashun; Peng, Shaoyi ^[1]

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1. Institute of Coal Chemistry, Taiyuan (China)

Samples of Cu-Co mixed oxide with Cu/Co = 0.25 to 1.0 (atomic ratio) were prepared by coprecipitation with Na{sub 2}CO{sub 3} and were characterized with TG, DSC, XRD, and XPS. Exothermic DSC peaks were observed at 588 and 808 K for Cu/Co = 0.25, and at 588, 643, and 683 K for Cu/Co = 1.0. The formation of Cu-Co spinel was observed by XRD after calcination of the sample at 623 K, and increased with prolonged heating at this temperature. But calcination at 773 K for 4 hr destroyed the spinel, producing CuO crystallites. Therefore, Cu-Co spinel is formed above 588 K and is stable at least up to 623 K for Cu-Co {le} 1.0. The thermal stability of Cu-Co spinel decreases with increasing Cu/Co ratio. The electron binding energies of Cu 2p{sub 3/2}, Co 2p{sub 3/2}, and O 1s are appreciably higher than those in pure CuO and Co{sub 3}O{sub 4}. For samples with a bulk Cu/Co ratio of 0.25, the surface ratio found by XPS is 0.35, while for Cu/Co = 1.0, the surface ratio is 0.55, indicating surface enrichment of Cu-Co spinel. It was also found that the Cu-Co spinel-enriched surface has a lower affinity for oxygen species than that of the pure oxides.

• OSTI ID: 6067368
• Journal Information: Journal of Solid State Chemistry; (USA), Journal Name: Journal of Solid State Chemistry; (USA) Vol. 89:1; ISSN 0022-4596; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
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Cermets
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
BINDING ENERGY
CALORIMETRY
CATALYSTS
CHALCOGENIDES
COBALT COMPOUNDS
COBALT OXIDES
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
DATA
DIFFERENTIAL THERMAL ANALYSIS
DIFFRACTION
ELECTRON SPECTROSCOPY
ENERGY
EXPERIMENTAL DATA
INFORMATION
MEASURING METHODS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
SCATTERING
SPECTROSCOPY
THERMAL ANALYSIS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION