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Hydroxy-Chromium Smectite: Influence of Cr Added

Published online by Cambridge University Press:  28 February 2024

C. Volzone
C. Volzone*
Affiliation:
Centro de Tecnología de Recursos Minerales y Cerámica, Cno. Centenario y 506, CC 49 (1897), M.B. Gonnet Buenos Aires, Argentina. FAX 54-21-710075
*
a54-21-710075
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Abstract

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OH-Cr smectites were prepared with different mmol Cr/g smectite: 0.5, 1.5, 3.5, 5, 10 and 20 by treatment with hydroxy-chromium solution prepared at 60°C and one day of hydrolysis with OH/Cr = 2. The samples were characterized by X-ray diffraction (XRD), differential thermal analyses (DTA) and N2 adsorption-desorption isotherms.

The d(001) spacings of OH-Cr-smectite were different according to Cr added/g smectite. Larger d(001) spacings: 1.95, 2.05 and 2.07 nm were obtained with 5, 10 and 20 mmol Cr per gram of sample. DTA diagrams of smectite treated with OH-Cr solution showed exothermic peak at 420°C corresponding to Cr203 (confirmed by XRD). N2 adsorption-desorption isotherms of smectite treated with different amounts of Cr preserved the same slit-shaped pores than original sample, but with different micropore volume. This behavior was maintained until treatment temperature of 380°C. The specific area of smectite was increased from 36 to 175 m2/g after treatment with OH-Cr solution. The textural characteristics of OH- Cr smectite heated up to 420°C were changed. The specific area decreased and mesopore volume was produced. The different Cr added modified the structural and textural behavior.

Keywords

DTAPillared claysSmectiteXRD
Type
Research Article
Information
Clays and Clay Minerals , Volume 43 , Issue 3 , June 1995 , pp. 377 - 382
Copyright
Copyright © 1995, The Clay Minerals Society

References

Barret, E. P., Joyner, L. G., and Halenda, P. H. 1961. The determination of pore volume and area distribution in porous substances. I Computation from nitrogen isotherms. J. Am. Chem. Soc. 73: 373–380.Google Scholar
Brindley, G. W., and Yamanaka, S. 1979. A study of hydroxychromium montmorillonites and the form of the hydroxy-chromium polymers. Am. Mineralog. 64: 830–835.Google Scholar
Carr, M. R., 1985. Hydration states of interlamellar chromium ions in montmorillonite. Clay & Clay Miner. 33: 357–361.CrossRefGoogle Scholar
Dandy, A. J., and Nadiye-Tabbiruka, N. S. 1975. The effect of heating in vacuo on the microporosity of sepiolite. Clays & Clay Miner. 23: 428–430.Google Scholar
Drljaca, A., Anderson, J. R., Spiccia, L., and Turney, T. W. 1992. Intercalation of montmorillonite with individual chromium (III) hydrolytic oligomers. Inorg. Chem. 31: 4894–4897.CrossRefGoogle Scholar
Figueras, F., 1988. Pillared clays as catalysts. Catal. Rev. Sci. Eng. 30: 457–499.Google Scholar
Gregg, S. J., and Sing, K. S. W. 1991. Adsorption Surface Area and Porosity. 2nd Edition. London: Academic Press, 303 pp.Google Scholar
Grim, R. E., and Kulbicki, B. 1961. Montmorillonite: High temperature reactions and classification. Am. Mineralog. 46: 1329–1369.Google Scholar
Lippens, B. C., and de Boer, J. H. 1965. Studies on pore systems in catalysts. J. Catal. 4: 319–323.CrossRefGoogle Scholar
Loeppert, R. H., and Mortland, M. M. 1979. The influence of heat-stable intercalate on the rate of dehydroxylation of smectite. Clays & Clay Miner. 27: 373–376.Google Scholar
Orr, C., and Dalla Valle, J. M. 1959. Fine Particle Measurement Size, Surface and Pore Volume. New York: The MacMillan Co., 27 pp.Google Scholar
Pierce, C., 1953. Computation of pore size from physical adsorption data. J. Phys. Chem. 57: 149–152.Google Scholar
Pinnavaia, T. J., Tzou, M. S., and Landau, S. D. 1985. New Chromia pillared clay catalysts. J. Am. Chem. Soc. 107: 4783–4785.Google Scholar
Rengasamy, P., and Oades, J. M. 1978. Intercalation of monomelic and polymeric species of metal ions with clay surfaces. III. Aluminium (III) and chromium (III). Aust. J. Soil Res. 16: 53–66.CrossRefGoogle Scholar
Spiccia, L., Stoeckli-Evans, H., Marty, W., and Giovanoli, R. 1983. A new “active” chromium(III) hydroxyde: Cr2(μ-OH)2(OH)4.2H2O). Characterization and use in the preparation of salts of the (H2O)4Cr((μ-OH)2(OH)4+4 ion. Crystal structure of [(H2O)4Cr((μ-OH2)4] [(H3C)3C6H2SO3]4.4H2O. Inorg. Chem. 26: 474–482.Google Scholar
Spiccia, L., Marty, W., and Giovanoli, R. 1988. Hydrolytic trimer of chromium (III). Synthesis through chromite cleavage and use in the preparation of the “active” trimer hydroxide. Inorg. Chem. 27: 2660–2666.Google Scholar
Stünzi, H., and Marty, W. 1983. Early stages of the hydrolysis of chromium (III) in aqueous solution. 1. Characterization of a tetrameric species. Inorg. Chem. 22: 2145–2150.Google Scholar
Stünzi, H., Spiccia, L., Rotzinger, F. P., and Marty, W. 1989. Early stages of the hydrolysis of chromium (III) in aqueous solution. 4. Stability constant of the hydrolytic dimer, trimer and tetramer at 25°C and I = 1.0M. Inorg. Chem. 28: 66–71.Google Scholar
Tzou, M. S., and Pinnavaia, T. J. 1988. Chromia pillared clays. Cat. Today 2: 243–259.Google Scholar
Vaughan, D. E. W., and Lussier, R. J. Preparation of Molecular Sieves on Pillared Interlayered Clays (PILC). Proc. 5th. Int. Zeol. Conf. Rees, L. V. C., 1980 ed. London: Heyden Press, 94–101.Google Scholar
Vaughan, D. E. W., 1988. Recent development in pillared interlayered clays. Perspectives in molecular sieve science. Chapter 19. W. H. Flank and T. E. Whyte, eds. Washington, DC: American Chemical Society, 308–323.Google Scholar
Volzone, C., Cesio, A. M., Torres Sanchez, R. M., and Pereira, E. 1993. Hydroxy-chromium smectite. Clays & Clay Miner. 41: 702–706.Google Scholar
Wheler, A., 1955. Reaction Rates and Selectivity in Catalysts Pores in Catalysts, Vol. II. Emmet, P. H., ed. New York: Rainhold Publishing Corp, 118 pp.Google Scholar