Homogeneous catalytic oxidation of pyrocatechol in the presence of transition metal ions

1980 ◽  
Vol 13 (4) ◽  
pp. 373-378 ◽  
Author(s):  
V. M. Vorotyntsev ◽  
E. P. Kuznetsova ◽  
Yu. I. Pyatnitskii ◽  
G. I. Golodets
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Catalytic Oxidation ◽  
Transition Metal Ions

Homogeneous Catalytic Oxidation of Aqueous Sulfur(IV) by Transition Metal Ions, Part III: Effect of Iron(III), Copper(II) and Manganese(II) and Synergistic Catalysis

1988 ◽  
Vol 20 (10) ◽  
pp. 45-47 ◽  
Author(s):  
M. Reda
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Catalytic Oxidation ◽  
Catalytic Effect ◽  
Transition Metal Ions ◽  
Distilled Water ◽  
Synergistic Catalysis

The general effects of Fe(III), Cu(II) and Mn(II) on the homogeneous catalytic auto-oxidation of aqueous sulfur(IV) were investigated. The results indicated that Fe(III) and Mn(II) are effective catalysts, and Cu(II) has a slight catalytic effect compared with distilled water. The apparent synergisms existing between Mn(II) and Cu(II), Mn(II) and Fe(III), and Fe(III) and Cu(II) were investigated.

HREM Study of electron-induced surface radiation damage in ReO3

1991 ◽  
Vol 49 ◽  
pp. 636-637
Author(s):  
R. Ai ◽  
H.-J. Fan ◽  
L. D. Marks
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Oxides ◽  
Electron Irradiation ◽  
Transition Metal Oxides ◽  
Carbon Film ◽  
Transition Metal Ions ◽  
Surface Radiation ◽  
Valence Transition ◽  
Electron Microscopes

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.

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