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The Standard Gibbs Energy of Formation of Fe(II)Fe(III) Hydroxide Sulfate Green Rust

Published online by Cambridge University Press:  01 January 2024

Karina Barbara Ayala-Luis*
Affiliation:
Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C., Denmark
Christian Bender Koch
Affiliation:
Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C., Denmark
Hans Christian Bruun Hansen
Affiliation:
Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C., Denmark
*
* E-mail address of corresponding author: [email protected]
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Abstract

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Mixed FeIIFeIII hydroxides, commonly referred to as ‘green rusts’ (GRs), are important reactive phases in both man-made and natural geochemical systems. Determinations of the standard Gibbs energy of formation of GRs are needed to understand and predict the occurrence and possible reactions of GRs in these systems. Slow acid titration of crystalline green rust sulfate (GRSO4\$\end{document}) with the formation of magnetite was used as a novel method to determine the standard Gibbs energy of formation of GRSO4\$\end{document}, ΔfGo(GRSO4)\$\end{document}. Aqueous suspensions of GRSO4\$\end{document}, with pH slightly >8, were titrated slowly with 1 M H2SO4 until pH = 3 under strict anoxic conditions. Powder X-ray diffraction and Mössbauer analysis revealed that magnetite was the only solid phase formed during the initial part of the titration, where the equilibrium pH was maintained above 7.0. The ratio of Fe2+ release to consumption of protons confirmed the stoichiometry of dissolution of GRSO4\$\end{document} and the formation of magnetite at equilibrium conditions. The estimate of the absolute value of ΔfGo(GRSO4)\$\end{document} was −3819.43±6.44 kJ mol−1 + y × [ΔfGo(H2O(1))], where y is the number of interlayer water molecules per formula unit. The logarithm of the solubility product, log Ksp, was estimated to be −139.2±4.8 and is invariable with y. Using the new value for ΔfGo(GRSO4)\$\end{document}, the reduction potentials of several GRSO4\$\end{document}-Fe oxide couples were evaluated, with the GRSO4\$\end{document}-magnetite half cell showing the smallest redox potential at pH 7 and free ion activities of 10−3.

Type
Article
Copyright
Copyright © 2008, The Clay Minerals Society

References

Bard, A.J. Parsons, R. and Jordan, J., 1985 Standard Potentials in Aqueous Solution New York Marcel Dekker Inc. 848 pp.Google Scholar
Benali, O. Abdelmoula, M. Refait, P. and Genin, J.M.R., 2001 Effect of orthophosphate on the oxidation products of Fe(II)-Fe(III) hydroxycarbonate: The transformation of green rust to ferrihydrite Geochimica et Cosmochimica Acta 65 17151726 10.1016/S0016-7037(01)00556-7.CrossRefGoogle Scholar
Bernal, J.D. Dasgupta, D.R. and Mackay, A.L., 1959 The oxides and hydroxides of iron and their structural inter-relationships Clay Minerals Bulletin 4 1564 10.1180/claymin.1959.004.21.02.CrossRefGoogle Scholar
Bourrie, G. Trolard, F. Genin, J.M.R. Jaffrezic, A. Maitre, V. and Abdelmoula, M., 1999 Iron control by equilibria between hydroxy-Green Rusts and solutions in hydromorphic soils Geochimica et Cosmochimica Acta 63 34173427 10.1016/S0016-7037(99)00262-8.CrossRefGoogle Scholar
Cornell, R.M. and Schwertmann, R.M., 2003 The Iron Oxides: Structure, Properties, Reactions, Occurrences and Uses Weinheim, Germany Wiley-VCH 10.1002/3527602097 664 pp.CrossRefGoogle Scholar
Daniels, J.M. and Rosencwaig, A., 1969 Mössbauer spectroscopy of stoichiometric and non-stoichiometric magnetite Journal of Physics and Chemistry of Solids 30 15611571 10.1016/0022-3697(69)90217-0.CrossRefGoogle Scholar
Devidal, J.L. Dandurand, J.L. and Gout, R., 1996 Gibbs free energy of formation of kaolinite from solubility measurement in basic solution between 60 and 170°C Geochimica et Cosmochimica Acta 60 553564 10.1016/0016-7037(95)00430-0.CrossRefGoogle Scholar
Erbs, M. Hansen, H.C.B. and Olsen, C.E., 1999 Reductive dechlorination of carbon tetrachloride using iron(II) iron(III) hydroxide sulfate (green rust) Environmental Science and Technology 33 307311 10.1021/es980221t.CrossRefGoogle Scholar
Fadrus, H. and Maly, J., 1975 Suppression of iron(III) interference in determination of iron(II) in water by 1,10-phenanthroline method Analyst 100 549554 10.1039/an9750000549.CrossRefGoogle Scholar
Furukawa, Y. Kim, J.W. Watkins, J. and Wilkin, R.T., 2002 Formation of ferrihydrite and associated iron corrosion products in permeable reactive barriers of zero-valent iron Environmental Science and Technology 36 54695475 10.1021/es025533h.CrossRefGoogle ScholarPubMed
Genin, J.M.R. Ruby, C. Gehin, A. and Refait, P., 2006 Synthesis of green rusts by oxidation of Fe(OH)2, their products of oxidation and reduction of ferric oxyhydroxides; Eh-pH Pourbaix diagrams Comptes Rendus Geoscience 338 433446 10.1016/j.crte.2006.04.004.CrossRefGoogle Scholar
Häggström, L. Annersten, H. Ericsson, T. Wappling, R. Karner, W. and Bjarman, S., 1978 Magnetic dipolar and electric quadrupolar effects on Mössbauer-spectra of magnetite above Verwey transition Hyperfine Interactions 5 201214 10.1007/BF01021693.CrossRefGoogle Scholar
Hansen, H.C.B. and Rives, V., 2001 Environmental chemistry of iron(II)-iron(III) LDHs (Green rusts) Layered Double Hydroxides: Present and Future New York Nova Science Pub Inc. 469493.Google Scholar
Hansen, H.C.B. Borggaard, O.K. and Sørensen, J., 1994 Evaluation of the free energy of formation of Fe(II)-Fe(III) hydroxy-sulphate (green rust) and its reduction of nitrite Geochimica et Cosmochimica Acta 58 25992608 10.1016/0016-7037(94)90131-7.CrossRefGoogle Scholar
Hansen, H.C.B. Koch, C.B. Krogh, H.N. Borggaard, O.K. and Sørensen, J., 1996 Abiotic nitrate reduction to ammonium: key role of green rust Environmental Science and Technology 30 20532056 10.1021/es950844w.CrossRefGoogle Scholar
Hemingway, B.S., 1990 Thermodynamic properties for bunsenite, NiO, magnetite, Fe3O4, and hematite, Fe2O3, with comments on selected oxygen buffer reactions American Mineralogist 75 781790.Google Scholar
Kelsall, G.H. and Williams, R.A., 1991 Electrochemical-behavior of ferrosilicides (Fexsi) in neutral and alkaline aqueous-electrolytes. 1. Thermodynamics of Fe-Si-H2O systems at 298 K Journal of the Electrochemical Society 138 931940 10.1149/1.2085750.CrossRefGoogle Scholar
Koch, C.B., 1998 Structures and properties of anionic clay minerals Hyperfine Interactions 117 131157 10.1023/A:1012603712578.CrossRefGoogle Scholar
Koch, C.B. and Hansen, H.C.B., 1997 Reduction of nitrate to ammonium by sulphate green rust Advances in GeoEcology 30 373393.Google Scholar
Legrand, L. El Figuigui, A. Mercier, F. and Hausse, A., 2004 Reduction of aqueous chromate by Fe(II)/Fe(III) carbonate green rust: kinetic and mechanistic studies Environmental Science and Technology 38 45874595 10.1021/es035447x.CrossRefGoogle Scholar
Majzlan, J. Grevel, K.D. and Navrotsky, A., 2003 Thermodynamics of Fe oxides: Part II. Enthalpies of formationand relative stability of goethite (α-FeOOH), lepidocrocite (γ-FeOOH), and maghemite (γ-Fe2O3) American Mineralogist 88 855859 10.2138/am-2003-5-614.CrossRefGoogle Scholar
Majzlan, J. Navrotsky, A. and Schwertmann, U., 2004 Thermodynamics of iron oxides: Part III. Enthalpies of formationand stability of ferrihydrite (∼Fe(OH)3), schwert-mannite (∼FeO(OH)3/4(SO4)1/8), and ε-Fe2O3 Geochimica et Cosmochimica Acta 68 10491059 10.1016/S0016-7037(03)00371-5.CrossRefGoogle Scholar
Morel, F.M.M. and Hering, J.G., 1993 Principles and Applications of Aquatic Chemistry New York Wiley 588 pp.Google Scholar
Myneni, S.C.B. Tokunaga, T.K. and Brown, G.E., 1997 Abiotic selenium redox transformations in the presence of Fe(II,III) oxides Science 278 11061109 10.1126/science.278.5340.1106.CrossRefGoogle Scholar
Parker, V.B. and Khodakovskii, I.L., 1995 Thermodynamic properties of the aqueous ions (2+ and 3+) of iron and the key compounds of iron Journal of Physical and Chemical Reference Data 24 16991745 10.1063/1.555964.CrossRefGoogle Scholar
Parkhurst, D.L. and Appelo, C.A.J. (1999) User’s guide to PHREEQC (version 2): A computer program for speciation, batch-reaction, one-dimensional transport and inverse geochemical calculations. Water-Resources Investigations, U.S. Geological Survey Report 99-4256. Denver, Colorado.Google Scholar
Patrick, W.A. and Thompson, W.E., 1953 Standard electrode potential of the iron ferrous ion couple at 25°C Journal of the American Chemical Society 75 11841187 10.1021/ja01101a052.CrossRefGoogle Scholar
Phillips, D.H. Watson, D.B. Roh, Y. and Gu, B., 2003 Mineralogical characteristics and transformations during long-term operation of a zerovalent iron reactive barrier Journal of Environmental Quality 32 20332045 10.2134/jeq2003.2033.CrossRefGoogle ScholarPubMed
Randall, S.R. Sherman, D.M. and Ragnarsdottir, K.V., 2001 Sorption of As(V) on green rust (Fe4(II)Fe2(III) (OH)12SO4·3H2O) and lepidocrocite (γ-FeOOH): Surface complexes from EXAFS spectroscopy Geochimica et Cosmochimica Acta 65 10151023 10.1016/S0016-7037(00)00593-7.CrossRefGoogle Scholar
Refait, P. Bon, C. Simon, L. Bourrie, G. Trolard, F. Bessiere, J. and Genin, J.M.R., 1999 Chemical composition and Gibbs standard free energy of formation of Fe(II)-Fe(III) hydroxysulphate greenrust and Fe(II) hydroxide Clay Minerals 34 499510 10.1180/000985599546280.CrossRefGoogle Scholar
Robie, R.A. and Hemingway, B.S. (1995) Thermodynamic properties of minerals and related substances at 298.15 K and 1 Bar (105 pascals) pressure and at higher temperatures. U.S. Geological Survey Bulletin, 1452, 461 pp.Google Scholar
Rodriguez, J.J.S. and Gonzalez, J.E.G., 2006 Identification and formation of green rust 2 as an atmospheric corrosion product of carbon steel in marine atmospheres Materials and Corrosion-Werkstoffe und Korrosion 57 411417 10.1002/maco.200503942.CrossRefGoogle Scholar
Sadiq, M., 1997 Arsenic chemistry in soils: An overview of thermodynamic predictions and field observations Water, Air and Soil Pollution 93 117136.CrossRefGoogle Scholar
Simon, L. Francois, M. Refait, P. Renaudin, G. Lelaurain, M. and Génin, J.R., 2003 Structure of the Fe(II-III) layered double hydroxysulphate green rust two from Rietveld analysis Solid State Sciences 5 327334 10.1016/S1293-2558(02)00019-5.CrossRefGoogle Scholar
Stumm, W. and Morgan, J.J., 1996 Aquatic Chemistry. Chemical Equilibria and Rates in Natural Waters New York Wiley 1022 pp.Google Scholar
Taylor, R.M., 1980 Formation and properties of Fe(II)Fe(III) hydroxy-carbonate and its possible significance in soil formation Clay Minerals 15 369382 10.1180/claymin.1980.015.4.04.CrossRefGoogle Scholar
Tardy, Y. and Duplay, J., 1992 A method of estimating the Gibbs free-energies of formation of hydrated and dehydrated clay-minerals Geochimica et Cosmochimica Acta 56 30073029 10.1016/0016-7037(92)90287-S.CrossRefGoogle Scholar
Tremaine, P.R. and Leblanc, J.C., 1980 The solubility of magnetite and the hydrolysis and oxidation of Fe2+ in water to 300°C Journal of Solution Chemistry 9 415442 10.1007/BF00645517.CrossRefGoogle Scholar
Wagman, D.D., Evans, W.H., Parker, V.B., Schumm, R.H., Halow, I., Bailey, S.M., Churney, K.L., and Nuttall, R.L. (1982) The NBS tables of chemical thermodynamic properties — selected values for inorganic and C-1 and C-2 organic-substances in SI Units. Journal of Physical and Chemical Reference Data, vol. 11, supplement 2.Google Scholar