Artículo
Abstract:
Aqueous oxalic acid forms surface CrIII-oxalato complexes with suspended chromium(III) oxide particles; the FTIR spectra demonstrate that both carboxylate groups of the ligand are bound to surface CrIII. Surface complexation is followed by changes in the surface redox potential toward more negative values and by the dissolution of the oxide. The dissolving steady state potential is in the range -60 to -210 mV against SHE. During surface conditioning, traces of oxidants at the interface are reduced, and some reduced metal ions accumulate. Minor amounts of dissolved CrII are generated and can be collected at a vicinal ring electrode set at -60 mV. In agreement, dissolution kinetics suggest that generation of CrII by ligand-to-metal charge transfer within the surface complexes produces a large increase in the rate of phase transfer, as expected from the properties of CrIII and CrII. Added chromous salts also catalyze the dissolution through intervalence charge transfer within an oxalato-bridged CrIII-L-CrII surface dimeric complex. The rate of dissolution at 65 °C follows a Langmuir-Hinshelwood dependence on oxalic acid concentration, a power law (order 0.31) dependence on proton concentration, and an a + b[CrII]0.64 dependence on [Cr(II)]. The Langmuir-Hinshelwood parameters are interpreted in terms of the stability constant of the surface CrIII-oxalato complex. © 1997 American Chemical Society.
Registro:
| Documento: | Artículo |
| Título: | Surface complexation description of the dissolution of chromium(III) hydrous oxides by oxalic acid |
| Autor: | García Rodenas, L.A.; Iglesias, A.M.; Weisz, A.D.; Morando, P.J.; Blesa, M.A. |
| Filiación: | Unidad de Actividad Química, Comn. Nac. de Ener. Atómica, Avenida del Libertador 8250, 1429 Buenos Aires, Argentina INQUIMAE, Fac. de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina |
| Año: | 1997 |
| Volumen: | 36 |
| Número: | 27 |
| Página de inicio: | 6423 |
| Página de fin: | 6430 |
| Título revista: | Inorganic Chemistry |
| Título revista abreviado: | Inorg. Chem. |
| ISSN: | 00201669 |
| CODEN: | INOCA |
| Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v36_n27_p6423_GarciaRodenas |
Referencias:
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Citas:
---------- APA ----------
García Rodenas, L.A., Iglesias, A.M., Weisz, A.D., Morando, P.J. & Blesa, M.A. (1997) . Surface complexation description of the dissolution of chromium(III) hydrous oxides by oxalic acid. Inorganic Chemistry, 36(27), 6423-6430.Recuperado de https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v36_n27_p6423_GarciaRodenas [ ]
---------- CHICAGO ----------
García Rodenas, L.A., Iglesias, A.M., Weisz, A.D., Morando, P.J., Blesa, M.A. "Surface complexation description of the dissolution of chromium(III) hydrous oxides by oxalic acid" . Inorganic Chemistry 36, no. 27 (1997) : 6423-6430.Recuperado de https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v36_n27_p6423_GarciaRodenas [ ]
---------- MLA ----------
García Rodenas, L.A., Iglesias, A.M., Weisz, A.D., Morando, P.J., Blesa, M.A. "Surface complexation description of the dissolution of chromium(III) hydrous oxides by oxalic acid" . Inorganic Chemistry, vol. 36, no. 27, 1997, pp. 6423-6430.Recuperado de https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v36_n27_p6423_GarciaRodenas [ ]
---------- VANCOUVER ----------
García Rodenas, L.A., Iglesias, A.M., Weisz, A.D., Morando, P.J., Blesa, M.A. Surface complexation description of the dissolution of chromium(III) hydrous oxides by oxalic acid. Inorg. Chem. 1997;36(27):6423-6430.Available from: https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00201669_v36_n27_p6423_GarciaRodenas [ ]
