Molybdenum chemistry in molten LiCl-KCl eutectic: An electrochemical and absorption spectroscopy study of the concentration dependent stability of solutions of K3MoCl6 / Gabriel J.C., Vincent D., Bouteillon J., Poignet J.C., Volkovich V.A., Griffiths T.R. // Electrochimica Acta. - 1999. - V. 44, l. 25. - P. 4619-4629.

ISSN:

00134686

Type:

Article

Abstract:

The chemical behaviour of LiCl-KCl-K3MoCl6 solutions between 400 and 500 °C was investigated. They underwent slow decomposition, according to a concentration dependent disproportionation reaction yielding metallic molybdenum and a volatile black higher valency molybdenum compound, which corresponded with MoCl5. Chronopotentiometric determinations showed a single 3-electron reduction, yielding Mo. The process was slow with diffusion-controlled mass transfer. The concentration of the Mo(III) species, presumed in the form of MoCl63- ions, was determined using linear sweep voltametry and open circuit voltage measurements and the overall Mo(III) species concentration by chemical analysis. The results showed MoCl63- to be the predominant species in the melt and the presence of a previously proposed dinuclear species, Mo2Cl93-, could not be confirmed electrochemically. This arose to quantification errors in the determination of the electroactive species MoCl63- due to inherent problems in estimating the active surface area of the electrode. The electronic absorption spectrum of MoCl63- in LiCl-KCl eutectic at 400 °C is reported for the first time. Measurements were made above and below 0.045 mol dm-3 K3MoCl6, the concentration above which the disproportionation reaction was relatively slow. The results are discussed in detail and the spectroscopic parameters of the octahedral MoCl63- complex were calculated as: Dq = 1775 cm-1, B = 511 cm-1 and C = 1913 cm-1. Although an additional band, at 340 nm, appeared during disproportionation it could not be identified with any currently known polynuclear molybdenum chloro complex or oxychloro complex. It is probably associated with an intermediate in the disproportionation process. No spectral evidence was thus obtained in support of the formation of dinuclear molybdenum species.

Author keywords:

Index keywords:

Absorption spectroscopy; Decomposition; Electrochemical electrodes; Lithium compounds; Mass transfer; Molybdenum compounds; Potassium compounds; Voltage measurement; Linear sweep voltammetry; Lithium

DOI:

нет данных

Смотреть в Scopus:

https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032661017&partnerID=40&md5=a7d04640a32f9ad3c07391f71117330d

Соавторы в МНС:

—

Другие поля

Поле	Значение
Link	https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032661017&partnerID=40&md5=a7d04640a32f9ad3c07391f71117330d
Affiliations	Lab. d'Electrochimie Phys.-Chim. M., UMR 5631 INPG-CNRS, ENSEEG, Domn. U., St Martin D'Heres, France; Université Joseph Fourier, Grenoble, France; School of Chemistry, The University of Leeds, LS2 WT, Leeds, United Kingdom
References	Senderoff, S., Brenner, A., (1954) J. Electrochem. Soc., 101, p. 16; Senderoff, S., Mellors, G.W., (1967) J. Electrochem. Soc., 114, p. 556; Inman, D., Sethi, R.S., Spencer, R., (1971) J. Electroanal. Chem., 29, p. 137; Inman, D., Spencer, R., (1977) Advances in Extractive Metallurgy and Refining, IMM Paper, 12; White, S.H., Twardoch, U.M., (1987) J. Appl. Electrochem., 17, p. 225; Kipouros, G.J., Sadoway, D., (1988) J. Appl. Electrochem., 18, p. 823; Gabriel, J.C., Bouteillon, J., Poignet, J.C., Roman, J.M., (1994) J. Electrochem. Soc., 141, p. 2286; Griffiths, T.R., Potts, P.J., (1975) J. Chem. Soc. Dalton Trans., p. 344; Chilesotti, A., (1903) Gazz. Chim. Ital., 33, p. 354; Bucknall, W.R., Carter, S.R., Wardlau, W., (1927) J. Chem. Soc., p. 513; Amilius, Z., Van Laar, B., Rietveld, H.M., (1969) Acta. Cryst. B, 25, p. 400; Arkhipov, P., Baraboshkin, A.N., Valeev, Z.I., Martem'Yanova, Z.S., (1990) Electrokhimiya, 26, p. 1555; (1974) Handbook of Chemistry and Physics 55th Ed., p. 198. , R.C. Weast; Scheffier, T.B., Hussey, C.L., Seddon, K.R., Kear, C.M., Armitage, P.D., (1983) Inorg. Chem., 22, p. 199; Hubbard, H.v.st.a., Griffiths, T.R., (1987) J Chem. Soc. Faraday Trans., 83, p. 1215; Kazin, P.E., Subbotina, N.A., Zhirov, A.I., Zelentsov, V.V., Felin, M.G., (1989) Russ. J. Inorg. Chem., 34, p. 294; Lever, A.B.P., (1968) Inorganic Electronic Spectroscopy, p. 182. , Amsterdam: Elsevier Publishing Company; Carlin, R.T., Osteryoung, R.A., (1988) Inorg. Chem., 27, p. 1482; Denisov, N.T., Kobeleva, S.I., (1990) New J. Chem., 14, p. 69
Correspondence Address	Gabriel, J.C.; Domaine Universitaire, St Martin D'Heres, France
Publisher	Elsevier Science Ltd, Exeter, United Kingdom
CODEN	ELCAA
Language of Original Document	English
Abbreviated Source Title	Electrochim Acta
Source	Scopus