Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-10T09:48:12.678Z Has data issue: false hasContentIssue false
  • English
  • Français

The Quantity of Reduced Nickel in Synthetic Takovite: Effects of Preparation Conditions and Calcination Temperature

Published online by Cambridge University Press:  28 February 2024

Mark K. Titulaer ,
J. Ben H. Jansen  and
John W. Geus
Mark K. Titulaer
Affiliation:
Department of Geochemistry, Institute for Earth Sciences, University of Utrecht, Budapestlaan 4, P.O. Box 80.021, 3508 TA Utrecht, The Netherlands
J. Ben H. Jansen
Affiliation:
Bowagemi B.V., Prinses Beatrixlaan 20, 3972 AN Driebergen
John W. Geus
Affiliation:
Department of Inorganic Chemistry, University of Utrecht, Sorbonnelaan 16, P.O. Box 80.083, 3508 TB Utrecht, The Netherlands
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Takovite, Ni6Al2(OH)i6CO3-5H2O, with molar Ni/Al ratios of 2.5 and 3 is prepared by precipitation at pH levels of 7 and 10, periods of reaction of 3 and 20 hr, and calcination temperatures varying between 120° and 8 5 3°C. The quantity of reduced Ni is determined as a function of the calcination temperature, and the solid phases remaining after reduction are determined with XRD. The Ni/Al ratio, pH of precipitation, and calcination temperature are important preparation conditions. A precursor of a Ni/Al ratio of 2.5 precipitated at a pH-level of 10 exhibits on reduction metallic Ni particles of about 15 nm irrespective of the drying or calcination temperature. After reduction, a considerable amount of NaAlO2 is present. Metallic Ni particles of 6 nm are present in a reduced precursor of Ni/Al ratio of 2.5 precipitated at a pH-level of 7. The size of the Ni particles present in a reduced precursor of Ni/Al ratio of 3 precipitated at a pH-level of 10 rises from 4–8 nm to 16 nm after calcination at temperatures increasing from 120° to 853°C. The last precursor contains much less sodium, and shows after reduction a disordered NiO phase containing some alumina. Especially, the takovite with the molar Ni/Al ratio of 2.5, thoroughly washed to remove Na, and calcined at T ≤ 260°C before reduction of Ni provides a promising catalyst for the production of hydrogen-carbon monoxide flows out of methane and steam.

Keywords

CalcinationNickel particle sizeTakoviteTemperature programmed reduction
Type
Research Article
Information
Clays and Clay Minerals , Volume 42 , Issue 3 , June 1994 , pp. 249 - 258
Copyright
Copyright © 1994, Clay Minerals Society

Footnotes

*

This paper is a contribution of the Debye Institute, University of Utrecht, The Netherlands.

References

de Korte, P. H. M., Doesburg, E. B. M., de Winter, C. P. J., and van Reyen, L. L., (1985) Characterization of the interaction between nickel oxide and aluminum oxide in coprecipitated catalysts: Solid State Ionics 16, 73–80.CrossRefGoogle Scholar
Doesburg, E. B. M., Hakvoort, G., Schaper, H., and van Reyen, L. L., (1983) The morphology of coprecipitated nickel-alumina catalysts: Applied Catalysis 7, 85–90.CrossRefGoogle Scholar
Doesburg, E. B. M., de Korte, P. H. M., Schaper, H., and van Reyen, L. L., (1984) The sintering of coprecipitated nickel alumina catalysts: Applied Catalysis 11, 155–160.CrossRefGoogle Scholar
Kruissink, E. C., Alzamora, L. E., Orb, S., Doesburg, E. B. M., van Reijen, L. L., Ross, J. H. R., and van Veen, G., (1979) Stud. in Surf. Sci. and Catal. 3, Preparation of Catalysts 2, Proceedings of the Second International Symposium, Louvain-la-Neuve, September 4–7 (1978), B. Delmon, P. Grange, P. Jacobs, and G. Poncelet, eds., Elsevier Amsterdam, 143–157Google Scholar
Kruissink, E. C., and van Reyen, L. L., (1981) Coprecipitated nickel-alumina catalysts for methanation at high temperature: J. Chem. Soc., Faraday Trans. 77(1), 649–663CrossRefGoogle Scholar
Miyata, S., (1980) Physico-chemical properties of synthetic hydrotalcites in relation to composition: Clays & Clay Minerals 28(1), 50–56.CrossRefGoogle Scholar