Hydrogenation of carbonyl compounds using tin-modified platinum-based catalysts prepared via surface organometallic chemistry on metals (SOMC/M)
Hydrogenation of carbonyl compounds using tin-modified platinum-based catalysts prepared via surface organometallic chemistry on metals (SOMC/M)
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DOI：
10.1016/s1381-1169(02)00188-7
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发表时间：
2002-07
影响因子：
--
通讯作者：
G. Santori;M. Casella;O. Ferretti
中科院分区：
文献类型：
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作者：
G. Santori;M. Casella;O. Ferretti
本文研究了含C - O和/或C - C键的化合物在锡修饰的硅负载铂基催化剂上的催化行为。利用金属表面有机化学（SOMC/M）技术引入了锡。通过对三种Sn/Pt原子比相同（0.4）但制备和活化温度不同的体系的研究，证明了注意条件对催化性能的影响。在丁醛和丁酮的加氢反应中，从几何和电子的角度看，η - 1-(O)型的吸附是非常有利的。在苯甲醛加氢反应中，PtSn-OM和PtSn-BM系统催化活性的增加比PtSn-OM *系统更重要，主要是由于与离子锡和苯基的存在有关的电子效应。在环己烯的情况下，几何效应、电子效应以及空间效应导致C - <s:1> C键氢化速率的强烈降低。这些结果可以外推解释不饱和α，β-醛的行为。锡促进了C - O基团的氢化，抑制了有利于C - C氢化的吸附模式。这两种效应的结合导致了对UOL的选择性顺序：Pt⪡PtSn- om∗< PtSn -BM<PtSn- om。
The catalytic behaviour of some compounds containing CO and/or CC bonds has been studied over silica-supported platinum-based catalysts, modified with tin. Tin was introduced by means of surface organometallic chemistry on metals (SOMC/M) techniques. The effect of the obtention conditions upon the catalytic performance was evidenced through the study of three systems having the same Sn/Pt atomic ratio (0.4), but prepared and activated at different temperature. In the hydrogenation of butyraldehyde and butanone, the adsorption of the η1-(O) type appears as highly favourable, both from a geometric and electronic point of view. In the benzaldehyde hydrogenation, the increase in the catalytic activity for PtSn-OM and PtSn-BM systems is quite more important than in the PtSn-OM∗system, fundamentally by electronic effects associated with the presence of ionic tin and of the phenyl group. In the case of the cyclohexene, geometric and electronic, as well as steric effects lead to a strong reduction of the hydrogenation rate of CC bond. These results can be extrapolated to explain the behaviour of the unsaturated α,β-aldehydes. The hydrogenation of the CO group is promoted and the adsorption modes favourable to the CC hydrogenation are inhibited by tin. The combination of both effects leads to the sequence of selectivity to UOL: Pt⪡PtSn-OM∗< PtSn -BM<PtSn-OM.