Mendeleev Commun., 2015, 25, 367–369
R
emarkably, the selectivity in DPA hydrogenation was distinctly
References
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1
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a significant increase in the r /r ratio (Table 2). Kinetic measure-
1
2
2
3
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1
2
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4
Detailed kinetic analysis of the relationship between TOF1,
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2
5
6
7
8
9
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2
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1
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2
This is in a good agreement with published data indicating
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2
3 D. Duca, F. Frusteri, A. Parmaliana and G. Deganello, Appl. Catal. A,
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1
2
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1
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1
9 A. Yu. Stakheev, I. S. Mashkovsky, G. N. Baeva and N. S. Telegina,
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of individual alkyne and alkene molecules. In our study we
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consecutive hydrogenation of the same molecule, which leads to
a significant improvement of the selectivity of semihydrogenation.
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2
0 V. P. Ananikov, L. L. Khemchyan, Yu. V. Ivanova, V. I. Bukhtiyarov,
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9
of hydrogen to the adsorbed alkyne or alkene molecule. This
2
2
1 S. Ichikawa, H. Poppa and M. Boudart, J. Catal., 1985, 91, 1.
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2
7
molecule followed by desorption of the hydrogenated product.
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2
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with several surface atoms. Therefore, this step proceeds faster
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2
5 B. Nohair, C. Especel, G. Lafaye, P. Marecot, L. C. Hoang and J. Barbier,
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9
rate-limiting step, which proceeds over a single metal atom.
2
8 I. Horiuti and M. Polanyi, Trans. Faraday Soc., 1934, 30, 1164.
This makes TOF essentially independent of the size of Pd
2
particles.
Thus, we found that the variation of Pd particle size provides
an effective tool for tuning activity–selectivity parameters in the
selective semihydrogenation of substituted alkynes due to different
structure sensitivities of the first and second hydrogenation steps.
This study was supported by the Russian Science Foundation
(grant no. 14-50-00126).
Received: 24th April 2015; Com. 15/4609
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