Abstract
All commercial catalysts for methanol synthesis and for the water–gas shift reaction in the low temperature region contain zinc oxide in addition to the main active component, copper. The varied benefits of zinc oxide are analysed here. The formation of zincian malachite and other copper/zinc hydroxy carbonates is essential in the production of small, stable copper crystallites in the final catalyst. Further, the regular distribution of copper crystallites on the zinc oxide phase ensures long catalyst life. Zinc oxide also increases catalyst life in the water–gas shift process by absorbing sulphur poisons but it is not effective against chloride poisons. In methanol synthesis, zinc oxide (as a base) removes acidic sites on the alumina phase which would otherwise convert methanol to dimethyl ether. Although bulk reduction of zinc oxide to metallic zinc does not take place, reduction to copper–zinc alloy (brass) can occur, sometimes as a surface phase only. A new interpretation of conflicting measurements of adsorbed oxygen on the copper surfaces of methanol synthesis catalysts is based on the formation of Cu–O–Zn sites, in addition to oxygen adsorbed on copper alone. The possible role of zinc oxide as well as copper in the mechanisms of methanol synthesis is still the subject of controversy. It is proposed that, only under conditions of deficiency of adsorbed hydrogen on the copper phase, hydrogen dissociation on zinc oxide, followed by hydrogen spillover to copper, is significant.
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G.W. Bridger and M.S. Spencer, in: Catalyst Handbook, 2nd Ed., ed. M.V. Twigg (Wolfe Publishing, London, 1989) ch. 9.
L. Lloyd, D.E. Ridler and M.V. Twigg, in: Catalyst Handbook, 2nd Ed., ed. M.V. Twigg(Wolfe Publishing, London, 1989) ch. 6.
K. Klier, Adv. Catal. 31(1982) 243.
G.C. Chinchen, P.J. Denny, D.G. Parker, G.D. Short, M.S. Spencer, K.C. Waugh and D.A. Whan, Prepr. Am. Chem. Soc., Div. Fuel Chem. 29 (1984) 178.
J.C.J. Bart and R.P.A. Sneeden, Catal. Today 2 (1987) 1.
G.C. Chinchen, M.S. Spencer, K.C. Waugh, and D.A. Whan, J. Chem. Soc., Faraday Trans. I 83 (1987) 2193.
G.C. Chinchen, P.J. Denny, J.R. Jennings, M.S. Spencer and K.C. Waugh, Appl. Catal. 36(1988) 1.
D. Waller, D. Stirling, F.S. Stone and M.S. Spencer, Faraday Disc. Chem. Soc. 87 (1989) 107.
A.M. Pollard, M.S. Spencer, R.G. Thomas, P.A. Williams, J.R. Jennings and J. Holt, Appl. Catal. A 85 (1992) 1.
P. Porta, S. de Rossi, G. Ferraris, M. Lo Jacono and G. Minelli, J. Catal. 109 (1988) 367.
Faraday Disc. 105 (1997) 395.
M.S. Spencer, in: Catalyst Handbook, 2nd Ed., ed. M.V. Twigg (Wolfe Publishing, London, 1989) ch. 1.
M.S. Spencer, Nature 323 (1986) 685.
K. Tohji, Y. Udagawa, T. Mizushima and A. Veno, J. Phys. Chem. 89 (1985) 5671.
Y. Okamoto, K. Fukino, T. Imanaka and S. Teranishi, J. Phys. Chem. 87 (1983) 3747.
A. Ludviksson, K.H. Ernst, R. Zhang and C.T. Campbell, J. Catal. 141 (1993) 380.
D. Stirling, F.S. Stone and M.S. Spencer, in: New Frontiers in Catalysis, Proc. 10th Internat. Congress Catal., Part B, eds. L. Guczi, F. Solymosi and P. Tétényi (Akadémiai Kiado, Budapest, 1993) p. 1507.
P.J.H. Carnell, in: Catalyst Handbook, 2nd Ed., ed. M.V.Twigg (Wolfe Publishing, London, 1989) ch. 4.
H.-J. Freund and M.W. Roberts, Surface Sci. Rep. 25 (1996) 225.
M.S. Spencer and R.H. Logan, unpublished.
G.W. Bridger and M.S. Spencer, in: Catalyst Handbook, 2nd Ed., ed. M.V. Twigg (Wolfe Publishing, London, 1989) ch. 9, p. 458.
G.C. Chinchen, K. Mansfield and M.S. Spencer, CHEMTECH 20 (1990) 692.
M.S. Spencer, Surface Sci. 192 (1987) 323.
M.S. Spencer, Surface Sci. 192 (1987) 329.
M.S. Spencer, Surface Sci. 192 (1987) 336.
T. van Herwijnen and W.A. de Jong, J. Catal. 34 (1974) 209.
T. Fujitani, M. Saito, Y. Kanai, T. Kakumoto, T. Watanabe, J. Nakamura and T. Uchijima, Catal. Lett. 25 (1994) 271.
Y. Kanai, T. Watanabe, T. Fujitani, M. Saito, J. Nakamura and T. Uchijima, Catal. Lett. 27 (1994) 67.
J. Nakamura, I. Nakamura, T. Uchijima, Y. Kanai, T. Watanabe, M. Saito and T. Fujitani, Catal. Lett. 31 (1995) 325.
J. Nakamura, T. Uchijima, Y. Kanai and T. Fujitani, Catal. Today 28 (1996) 223.
R. Burch, S.E. Golunski and M.S. Spencer, J. Chem. Soc., Faraday Trans. 86 (1990) 2683.
M.S. Spencer, Surface Sci. 339 (1995) L897.
M. Muhler, E. Törnqvist, L.P. Nielsen, B.S. Clausen and H. Topsøe, Catal. Lett. 25 (1994) 1.
C.T. Campbell, Appl. Catal. 32 (1987) 367.
J.A. Rodriguez, W.D. Glendenning and C.T. Campbell, J. Phys. Condens. Matter I (1989) SB149.
M.S. Spencer, to be published.
M.W. Roberts, Chem. Soc. Rev. (1996) 437.
G.C. Chinchen and M.S. Spencer, Catal. Today 10 (1991) 293.
G.C. Chinchen, P.J. Denny, D.G. Parker, M.S. Spencer and D.A. Whan, Appl. Catal. 30 (1987) 333.
G.C. Chinchen, K.C. Waugh and D.A. Whan, Appl. Catal. 25 (1986) 101.
B. Denise, R.P.A. Sneeden, B. Beguin and O. Cherifi, Appl. Catal. 30 (1987) 353.
I.A. Fisher, H.C. Woo and A.Y. Bell, Catal. Lett. 44 (1997) 11.
R. Burch, R.J. Chappell and S.E. Golunski, J. Chem. Soc., Faraday Trans. I85 (1989) 3569.
P.R. Dennison, K.J. Packer and M.S. Spencer, J. Chem. Soc., Faraday Trans. I 85 (1989) 3537.
M.S. Spencer, Catal. Lett. 50 (1998) 37.
R. Burch, S.E. Golunski and M.S. Spencer, Catal. Lett. 5 (1990) 55.
R. Burch, S.E. Golunski and M.S. Spencer, Catal. Lett. 6 (1990) 152.
F.S. Stone, Faraday Discuss. 105 (1997) 398.
J.M. Campbell and C.T. Campbell, Surface Sci. 259 (1991) 1.
K.-H. Ernst, C.T. Campbell and G. Moretti, J. Catal. 134 (1992) 66.
S. Bailey, G.F. Froment, J.W. Snoeck and K.C. Waugh, Catal. Lett. 30 (1995) 99.
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Spencer, M. The role of zinc oxide in Cu/ZnO catalysts for methanol synthesis and the water–gas shift reaction. Topics in Catalysis 8, 259–266 (1999). https://doi.org/10.1023/A:1019181715731
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DOI: https://doi.org/10.1023/A:1019181715731