2014-Sustainable Industrial Processing Summit
SIPS 2014 Volume 6: Rare Earths & Ionic Liquids
| Editors: | Kongoli F |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2014 |
| Pages: | 432 pages |
| ISBN: | 978-1-987820-08-9 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Synthesis of Novel Compounds and Nanomaterials in Molten Salts
Sergey Kuznetsov1;1INSTITUTE OF CHEMISTRY, KOLA SCIENCE CENTRE RAS, Apatity, Russian Federation;
Type of Paper: Regular
Id Paper: 56
Topic: 11
Abstract:
Our long term electrochemical investigations of halide-oxyfluoride molten systems resulted in the electrochemical synthesis of early unknown in literature compounds of niobium and tantalum. These elements are to a certain extent chemical analogs. Nevertheless, the cathodic products of electrolytic processes carried out in similar Nb-and Ta-containing melts are very different.
For the Nb-containing melts the most typical cathodic products are low valence compounds: Nb, Nb(O), NbO', Nb4O5, tetragonal suboxide Nb6O, rombohedral suboxide NbxO (x. For Ta-containing melts, the most characteristic cathodic products are metal-like conducting oxide bronzes of three structural types: cubic, tetragonal and hexagonal for the potassium compounds K1-xTaO3, K6-xTa10.8O30 and K6Ta6.5O15+xF6+y respectively while the cesium phases, with pyrochlore type lattice, have the general formula Csn+2+zO5+yF1-y.
For the first time by electrochemical synthesis from NaCl-KCl-NaF-GdF3-KBF4 melt at temperature 1023 K and with utilization of molybdenum cathode, the gadolinium hexaboride nanotubes were synthesized. Most likely GdB6 nanotubes formation is ruled by intercalation mechanism.
Nanoneedles of TaO with tetragonal crystal lattice were obtained by electrolysis of CsCl melt, containing monooxofluoride complexes of tantalum. It was determined the correlation between the redox potential of molten system, temperature and stability of tantalum monoxide.
A new generation of highly active and stable nanostructured catalytic coatings for the water-gas shift reaction by high-temperature electrochemical synthesis in molten salts has been developed.