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Author Ballivet-Tkatchenko, D. ♦ Branco, J. ♦ Matos, A. P. de
Sponsorship USDOE
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ CHEMISTRY ♦ INTERMETALLIC COMPOUNDS ♦ OXIDATION ♦ COPPER ALLOYS ♦ LANTHANUM ALLOYS ♦ CERIUM ALLOYS ♦ PRASEODYMIUM ALLOYS ♦ NEODYMIUM ALLOYS ♦ HYDROCARBONS ♦ DECOMPOSITION ♦ X-RAY DIFFRACTION ♦ CATALYSTS ♦ TEMPERATURE RANGE 0400-1000 K ♦ CRYSTAL STRUCTURE ♦ THERMAL GRAVIMETRIC ANALYSIS ♦ OXIDES
Abstract The air-oxidation of the intermetallic compounds LaCu{sub 2}, CeCu{sub 2}, PrCu{sub 2}, and NdCu{sub 2} was followed by thermogravimetry. The mass uptake occurred over a wide range of temperature (423-1100 K), leading to two stoichiometrics according to the lanthanide; CeCu{sub 2}O{sub 4} and LnCu{sub 2}O{sub 3.5} (Ln = La, Pr, Nd). The characterization by powder X-ray diffraction, scanning electron microscopy/energy dispersive X-ray analysis, and surface area measurements showed that segregation took place with the formation of CuO along with CeO{sub 2} or Ln{sub 2}CuO{sub 4} (Ln = La, Pr, Nd). Therefore, the oxidized intermetallics are better described by the formulas CeO{sub 2}{center_dot}2CuO and Ln{sub 2}CuO{sub 4}{center_dot}3CuO. The oxidation process noticeably increased the surface areas and promoted CuO migration to the surface. These systems exhibited selectivities in 4-methyl-2-pentanol decomposition, which are associated with the lanthanide. 34 refs., 4 figs., 3 tabs.
ISSN 00223654
Educational Use Research
Learning Resource Type Article
Publisher Date 1995-04-13
Publisher Place United States
Journal Journal of Physical Chemistry
Volume Number 99
Issue Number 15


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