Abstract
The feasibility of producing ammonia synthesis catalysts from high‐energy ball‐milling of a simple mixture of the constituent oxides has been investigated. The effect of ball‐milling the fused oxidic precursor of the industrial KM1 ammonia synthesis catalyst has also been studied. The results show that high‐energy ball‐milling offers some interesting possibilities for preparing novel catalytic materials. It is observed that ball‐milling of the powder oxides mixture leads to formation of solid solutions and the catalytic activity is significantly higher than that of the starting material. Furthermore, ball‐milling of fused oxidic KM1 precursor is seen to give rise to more homogeneous promoter distribution and slightly higher activity. The quite small activity increase observed in this case probably reflects the fact that the fusion process has already resulted in a close to optimal promoter distribution. The choice of atmosphere during ball‐milling is also seen to offer possibilities for regulating the phase composition.
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References
R. Schlögl, in: Catalytic Ammonia Synthesis — Fundamentals and Practice, ed. J.R. Jennings (Plenum, New York, 1991) p. 19.
P. Stoltze, in: Ammonia — Catalysis and Manufacture, ed. A. Nielsen (Springer, Berlin, 1995) p. 16.
A. Nielsen, An Investigation on Promoted Iron Catalysts for the Synthesis of Ammonia, 3rd Ed. (Jul. Gjellerup, 1968).
B.S. Clausen, S. Mørup, H. Topsøe, R. Candia, E.J. Jensen, A. Baranski and A. Pattek, J. Phys. Colloq. 37 (1976) C6-245.
W.L. Johnson, Prog. Mater. Sci. 30 (1986) 81.
C.C. Koch, in: Materials Science and Technology, Vol. 15, eds. R.W. Cahn, P. Haasen and E.J. Kramer (VCH, Weinheim, 1991) p. 193.
J.Z. Jiang, C. Gente and R. Bormann, Mater. Sci. Eng. A 242 (1998) 268.
J.Z. Jiang, R. Lin, S. Mørup, K. Nielsen, F.W. Poulsen, F.J. Berry and R. Clasen, Phys. Rev. B 55 (1997) 11; J.Z. Jiang, S. Mørup and S. Linderoth, Mater. Sci. Forum 225–227 (1996) 489; J.Z. Jiang, R.K. Larsen, R. Lin, S. Mørup, I. Chorkendorff, K. Nielsen, K. Hansen and K. West, J. Solid State Chem. 138 (1998) 114.
L. Huang, G.J. Kramer, W. Wieldraaijer, D.S. Brands, E.K. Poels, H.L. Castricum and H. Bakker, Catal. Lett. 48 (1997) 55.
T. Rühle, D. Herein, N. Pfander, G. Weinberg, T. Braum and R. Schlögl, Oral presentation at XXIX Jahrestreffen deutscher Katalytiker, Friedrichroda, 20–22 March 1996.
F.C. Jentoft, H. Schmelz and H. Knözinger, Appl. Catal. A 161 (1997) 167.
A. Trovarelli, F. Zamar, J. Llorca, C. de Leitenburg, G. Dolcetti and J.T. Kiss, J. Catal. 169 (1997) 490; A. Trovarelli, P. Matteazzi, G. Dolcetti, A. Lutman and F. Miani, Appl. Catal. A 95 (1993) L9; F. Zamar, A. Tovarelli, C. de Leitendam and G. Dolcetti, in: 11th Int. Congr. on Catalysis, Stud. Surf. Sci. Catal., Vol. 101B, eds. J.W. Hightower, W.N. Delgass, E. Iglesia and A.T. Bell (Elsevier, Amsterdam, 1996) p. 1283.
V.A. Zazhigalov, J. Haber, J. Stoch, L.V. Bogutskaya and I.V. Bacherikova, Appl. Catal. A 135 (1996) 155; V.A. Zazhigalov, J. Haber, J. Stoch, L.V. Bogutskaya and I.V. Bacherikova, in: 11th Int. Congr. on Catalysis, Stud. Surf. Sci. Catal., Vol. 101B, eds. J.W. Hightower, W.N. Delgass, E. Iglesia and A.T. Bell (Elsevier, Amsterdam, 1996) p. 1039.
M. Crocker, R.H.M. Herold, C.A. Emeis and M. Krijger, Catal. Lett. 15 (1992) 339.
S. Mori, W.C. Xu, T. Ishidzuki, N. Ogasawara, J. Imai and K. Kobayashi, Appl. Catal. A 137 (1996) 255.
L.T. Weng, N. Spitaels, B. Yasse, J. Ladrire and P. Ruiz, J. Catal. 132 (1991) 319.
J.Z. Jiang, Y.X. Zhou, S. Mørup and C.B. Koch, Nanostruct. Mater. 7 (1996) 401; S. Linderoth, J.Z. Jiang and S. Mørup, Mater. Sci. Forum 235–238 (1997) 205.
S. Mørup, B.S. Clausen and P.H. Christensen, J. Magn. Magn. Mater. 68 (1987) 160.
S.R. Tennison, in: Catalytic Ammonia Synthesis — Fundamentals and Practice, ed. J.R. Jennings (Plenum, New York, 1991) p. 305 (see figure 9.1(b)).
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Jacobsen, C.J., Jiang, J., Mørup, S. et al. Ammonia synthesis over multi‐promoted iron catalysts obtained by high‐energy ball‐milling. Catalysis Letters 61, 115–120 (1999). https://doi.org/10.1023/A:1019041426284
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DOI: https://doi.org/10.1023/A:1019041426284