Abstract
Tako vi te, 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.
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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 co-precipitated catalysts: Solid State Ionics 16, 73–80.
Doesburg, E. B. M., Hakvoort, G., Schaper, H., and van Reyen, L. L. (1983) The morphology of coprecipitated nick-elalumina catalysts: Applied Catalysis 7, 85–90.
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.
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, 143–157
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), 649–663
Miyata, S. (1980) Physico-chemical properties of synthetic hydrotalcites in relation to composition: Clays & Clay Minerals 28(1), 50–56.
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This paper is a contribution of the Debye Institute, University of Utrecht, The Netherlands
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Titulaer, M.K., Jansen, J.B.H. & Geus, J.W. The Quantity of Reduced Nickel in Synthetic Takovite: Effects of Preparation Conditions and Calcination Temperature. Clays Clay Miner. 42, 249–258 (1994). https://doi.org/10.1346/CCMN.1994.0420303
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DOI: https://doi.org/10.1346/CCMN.1994.0420303