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Role of Structural Hydrogen in the Reduction and Reoxidation of Iron in Nontronite

Published online by Cambridge University Press:  02 April 2024

Paul R. Lear
Affiliation:
Department of Agronomy, University of Illinois, Urbana, Illinois 61801
Joseph W. Stucki
Affiliation:
Department of Agronomy, University of Illinois, Urbana, Illinois 61801
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Abstract

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The effects of reduction and reoxidation of octahedral Fe3+ on the exchange of structural hydrogen in nontronite were determined using tritium (3H) as a label element. The uptake of H from the surrounding solution of nontronite suspensions increased as the reduction of structural Fe3+ increased. Similarly, the loss of H from the structure increased as the reduction increased. The results are generally consistent with a reduction mechanism involving the loss of structural OH, leaving the affected Fe sites with less than six-fold coordination. The attenuation of increased negative charge on the clay layer, however, was less than predicted by such a mechanism.

During the reoxidation of reduced nontronite in suspension, about one-third of the H remaining as part of the structure following reduction was lost, whereas twice that amount of H was incorporated into the structure from the surrounding solution. A reoxidation mechanism is proposed whereby H2O from the surrounding solution is incorporated into the mineral structure followed by the elimination of a hydrogen ion, returning the Fe to six-fold coordination. This mechanism implies the reversibility of Fe reduction in nontronite.

Type
Research Article
Copyright
Copyright © 1985, The Clay Minerals Society

References

Addison, W. E., Sharp, J. H. and Swineford, A., 1963 Redox behavior of iron in hydroxylated silicates Clays and Clay Minerals, Proc. 11th Natl. Conf., Ottawa, Ontario, 1962 New York Pergamon Press 95104.Google Scholar
Anderson, W. L., Stucki, J. W., Mort-land, M. M. and Farmer, V. C., 1979 Effect of structural Fe2+ on visible absorption spectra of nontronite suspensions Proc. Int. Clay Conf., Oxford, 1978 Amsterdam Elsevier 7583.Google Scholar
Farmer, V. C., Russell, J. D., McHardy, W. J., Newman, A. C. D., Ahlrichs, J. L. and Rimsaite, J. Y. H., 1971 Evidence for loss of protons and octahedral iron from oxidized biotites and vermiculites Mineral. Mag. 38 121137.CrossRefGoogle Scholar
Foster, M. D., 1953 Geochemical studies of clay minerals: II. Relation between ionic substitution and swelling in montmorillonite Amer. Mineral. 38 9941006.Google Scholar
Foster, M. D., 1955 The relationship between composition and swelling in clays Clays and Clay Minerals, Proc. 3rd Natl. Conf, Houston, Texas, 1954 395 205220.Google Scholar
Goodman, B. A., Russell, J. D., Fraser, A. R. and Woodhams, F.W.D., 1976 A Mössbauer and I.R. spectroscopic study of the structure of nontronite Clays & Clay Minerals 24 5359.CrossRefGoogle Scholar
Heller-Kallai, L. and Rozenson, I., 1980 Dehydroxylation of dioctahedral phyllosilicates Clays & Clay Minerals 28 355368.CrossRefGoogle Scholar
McAuliffe, C. D., Hall, N. S., Dean, L. A. and Hendricks, S. B., 1947 Exchange reactions between phosphates and soils: hydroxylic surfaces of soil minerals: So/7 Sci. Soc. Amer. Proc. 12 119123.CrossRefGoogle Scholar
O’Neil, J. R. and Kharaka, Y., 1976 Hydrogen and oxygen isotope exchange reactions between clay minerals and water Geochim. Cosmochim. Acta 40 241246.CrossRefGoogle Scholar
Radoslovich, E. W., 1962 The cell dimensions and symmetry of layer lattice silicates. II. Regression relations Amer. Mineral. 47 617636.Google Scholar
Ross, G. J. and Rich, C. I., 1973 Changes in b-dimension in relation to potassium exchange and to oxidation of phlog-opite and biotite Clays & Clay Minerals 21 201204.CrossRefGoogle Scholar
Roth, C. B., Jackson, M. L. and Syers, J. K., 1969 Deferration effect on structural ferrous-ferric ratio and CEC of vermiculites and soils Clays & Clay Minerals 17 253264.CrossRefGoogle Scholar
Roth, C. B., Tullock, R. J. and Serratosa, J. M., 1973 Deprotonation of nontronite resulting from chemical reduction of structural ferric iron Proc. Int. Clay Conf, Madrid, 1972 Madrid Div. Ciencias C.S.I.C 107114.Google Scholar
Rouxhet, P., 1970 Kinetics of dehydroxylation and OH-OD exchange in macrocrystalline micas Amer. Mineral. 55 841853.Google Scholar
Roy, D. M. and Roy, R., 1957 Hydrogen-deuterium exchange in clays and problems in the assignment of infrared frequencies in the hydroxyl region Geochim. Cosmochim. Acta 11 7285.CrossRefGoogle Scholar
Rozenson, I. and Heller-Kallai, L., 1976 Reduction and oxidation of Fe3+ in dioctahedral smectite 1. Reduction with hydrazine and dithionite Clays & Clay Minerals 24 271282.CrossRefGoogle Scholar
Russell, J. D., Farmer, V. C. and Velde, B., 1970 Replacement of OH by OD in layer silicates, identification of the vibrations of those groups in infra-red spectra Mineral. Mag. 37 869879.CrossRefGoogle Scholar
Russell, J. D., Goodman, B. A. and Fraser, A. R., 1979 Infrared and Mössbauer studies of reduced nontronites Clays & Clay Minerals 27 6371.CrossRefGoogle Scholar
Serratosa, J. M., 1960 Dehydroxylation studies by infrared spectroscopy Amer. Mineral. 45 11011104.Google Scholar
Stucki, J. W., 1981 The quantitative assay of minerals for Fe 2+ and Fe3+ using 1,10-phenanthroline: II. A photochemical method Soil Sci. Soc. Amer. J. 45 638641.CrossRefGoogle Scholar
Stucki, J. W. and Anderson, W. L., 1981 The quantitative assay of minerals for Fe2+ and Fe3+ using 1,10-phenanthroline: I. Sources of variability Soil Sci. Soc. Amer. J. 45 633637.CrossRefGoogle Scholar
Stucki, J. W., Golden, D. C. and Roth, C. B., 1984 The preparation and handling of dithionite-reduced smectite suspensions Clays & Clay Minerals 32 191197.CrossRefGoogle Scholar
Stucki, J. W., Golden, D.C. and Roth, C.B., 1984 Effects of reduction and reoxidation of structural iron on the surface charge and the dissolution of dioctahedral smectites Clays & Clay Minerals 32 350356.CrossRefGoogle Scholar
Stucki, J. W., Low, P. F., Roth, C. B. and Golden, D. C., 1984 Effects of oxidation state of octahedral iron on clay swelling Clays & Clay Minerals 32 357362.CrossRefGoogle Scholar
Stucki, J. W. and Roth, C. B., 1976 Interpretation of infrared spectra of oxidized and reduced nontronite Clays & Clay Minerals 24 293296.CrossRefGoogle Scholar
Stucki, J. W. and Roth, C. B., 1977 Oxidation-reduction mechanism for structural iron in nontronite Soil Sci. Soc. Amer. J. 41 808814.CrossRefGoogle Scholar
Vedder, W. and Wilkins, R. W. T., 1969 Dehydroxylation and rehydroxylation, oxidation and reduction of micas Amer. Mineral. 54 482509.Google Scholar