- THERMODYNAMIC PROPERTIES OF CERIUM OXALATE AND CERIUM OXIDE.
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Differential scanning calorimetry and thermogravimetry were used to determine the thermodynamic properties of cerium oxalate. Hydrated cerium oxalate was found to contain 13 molecules of water and decomposed producing three thermal events corresponding to
- Gallagher,Dworzak
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- Synthesis of mesoporous cerium oxide (CeO2) nanoparticles and effect of cerium precursors on transamidation of acetamide with N-octylamine under solvent-free conditions
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Mesoporous cerium oxide (CeO2) nanoparticles act as an effective heterogeneous catalyst for the transamidation reaction of amides with amines. The mesoporous CeO2 nanoparticles were prepared by hydrothermal method using different cerium precursor such as: cerium(III) chloride heptahydrate [CeCl3? 7H2O], cerium nitrate hexahydrate [Ce(NO3)3 ? 6H2O], ceric ammonium nitrate [(NH4) 2Ce(NO3)6], and cerium(III) acetate [Ce(C2H3O2)3 ?1.5H2O]. It shows highest catalytic activity for transamidation of acetamide with N-octylamine under solvent free conditions. This is the first example of a heterogeneous catalyst for transamidation using aliphatic amines as substrates. The X-ray diffraction, BET surface area analysis, and FT-IR characterizations of CeO2 suggested its excellent catalytic activity for transamidation reaction.
- Kumar, Ashish,Sharma, Manu,Gautam, Rajeev K.,Agarwala, Pooja,Basu, Soumen
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- Ultrasonic-assisted solution-phase synthesis and property studies of hierarchical layer-by-layer mesoporous CeO2
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Hierarchical layer-by-layer quadrangle CeO2 was prepared through ultrasonic-assisted solution-phase synthesis strategy using cerium oxalate as the precursor. The as-prepared mesoporous CeO2 displayed a surface area of 98.7 m2 g?1 and pore diameters of 2.0–10.0 nm. The high-resolution TEM image revealed that the layer structures of the CeO2 were made of numerous nanocrystal particles with the crystallite size of about 13–15 nm. High energy and cavitation of ultrasonic wave assists cerium oxalate precursor in building the layer-by-layer quadrangle staking. UV–vis absorption spectrum showed that the direct allowed transition bandgap energy for the as-prepared CeO2 was 2.91 eV. Moreover, the CeO2 exhibited good photocatalytic property for degrading Rhodamine B solution under UV radiation.
- Zhao, Pu Su,Gao, Xiu Mei,Zhu, Feng Xia,Hu, Xin Ming,Zhang, Li Li
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p. 375 - 380
(2018/02/13)
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- AMINOPOLYCARBOXYLATES OF RARE EARTHS, 17. STUDIES ON THE FORMATION OF TERNARY COMPLEXES OF THE LANTHANIDE(III)-ETHYLENEDIAMINETETRAACETATES WITH OXALATE AND DIGLYCOLATE LIGANDS
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The stability constants of the ternary complexes formed between the lanthanide(III)-ethylenediaminetetraacetates and oxalate as well as diglycolate ligands have been determined by an indirect pH-potentiometric titration method.The trend of the stability constants is similar to that of the lanthanide(III)-oxalate and -diglycolate complexes of 1:1 metal to ligand ratio.The results suggest that in determining the stability constants the steric requirement of the secondary ligand is not the crucial factor but some specific metal - secondary ligand interactions may also play an important role.The 1H-NMR spectra of the ternary complexes reveal that the binding of the bidentate oxalate ligand has practically no effect on the coordination of the edta4-, but the conformation of the coordinated edta4- is changed when the terdentate diglycolate binds to the lanthanide(III) ion.
- Kiraly, Robert,Toth, Imre,Zekany, Laszlo,Bruecher, Ernoe
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p. 519 - 526
(2007/10/02)
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