Ga O ÈAl O [ Al O [ In O ÈAl O . It is reported that
support of the Centre National de la Recherche ScientiÐque
(CNRS) of France.
2
3
2 3
2 3
2 3 2 3
the 33DMB1 isomerisation proceeds via secondary carbenium
ions on BrÔnsted acid sites.39 However, Duprez et al.14,40
reported that this reaction proceeds on several aluminas that
generally possess no BrÔnsted acidity. Perot et al.,41,42 from a
study of the isomerisation of but-2-ene selectively deuterated
in the allylic and vinylic positions, claimed that alumina may
have a weak protonic acidity. In the present work, it was
revealed by DMP adsorption that there are a number of
BrÔnsted acid sites on the surface of all the catalysts (Fig. 3).
DMP adsorption showed that the number of BrÔnsted acid
sites on Al O was increased by addition of Ga O and
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2
3
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1
1
Obviously, they are quite similar for Al O
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1
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2
3
Ga O ÈAl O : 100 ^ 6 kJ mol~1. This is consistent with the
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3
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45.
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2
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13
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15
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1
2
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2 3 2 3
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3
2 3
1
8
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1
9
1
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3
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4
Conclusion
2
000, 192, 137.
Adsorption of probe molecules on alumina-based catalysts
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2
4 M. Haneda, Y. Kintaichi and H. Hamada, unpublished results.
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9
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2
3
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2
3
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3
2
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2
3
2 3
106, 157.
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3
4
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3
3
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38
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Acknowledgements
This work was carried out in the framework program of scien-
tiÐc collaboration between France and Japan (PICS FranceÈ
Japan). M. Haneda gratefully acknowledges the Ðnancial
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1370
Phys. Chem. Chem. Phys., 2001, 3, 1366È1370