Hydroprocessing of Substituted Benzenes Over a Sulfided CoO-MoO3/γ-Al2O3 Catalyst.
Hydroprocessing of Substituted Benzenes Over a Sulfided CoO-MoO3/γ-Al2O3 Catalyst.
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DOI：
10.1002/chin.199027091
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发表时间：
1990-07
期刊：
影响因子：
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通讯作者：
C. Moreau;J. Joffre;C. Saenz;P. Geneste
中科院分区：
文献类型：
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作者：
C. Moreau;J. Joffre;C. Saenz;P. Geneste
先前的论文（1，2）已经报道了取代的苯是用于评价常规硫化的NiMo/Al 2 O3加氢处理催化剂的氢解相对于环加氢活性的合适的模型化合物。取代苯加氢处理的两种反应路径如图1所示。我们已经证明，特别是，环氢化有利于强供电子取代基，如NH 2，NHC 6 H5，OH或OC 6 H5，而氢解有利于轻微供电子取代基，如SH，SC 6 H5，Cl或Br。此外，得到的Hammett型关联证实了有机分子的芳香性对反应性的主要影响。这种相关性的存在构成了存在两个不同催化位点的第一个化学证据，一个负责苯环的氢化，与吸电子特征相关，另一个负责C，p2-X键的氢解，与供电子特征相关。关于取代苯的加氢处理的文献数据显示CoMo/Al 2 O3和NiMo/Al 2 O3催化剂表现不同。例如，甲基取代的酚的加氢脱氧主要通过在硫化的CoMo/Al 2 O3催化剂上的CO键的氢解进行（3），并且相关作者还提出了不同的活性位点负责两个反应路径（参见图1），一个用于CO键断裂，另一个用于氢化。在硫化的NiMo/Al 2 O3催化剂上，我们已经表明，被烷基、环烷基、环烷基取代的酚的加氢脱氧是有效的。
Previous papers (1, 2) have reported that substituted benzenes are suitable model compounds for evaluating the hydrogenolysis vs ring hydrogenation activity of a conventional sulfided NiMo/A1203 hydrotreating catalyst. The two reaction paths for the hydroprocessing of substituted benzenes are illustrated in Fig. 1. We have shown, in particular, that ring hydrogenation is favored by strongly electron-donating substituents such as NH2, NHC6Hs, OH, or OC6H5, whereas hydrogenolysis is favored by slightly electron-donating substitutents such as SH, SC6H5, C1, or Br. Moreover, the Hammett-type correlations obtained have confirmed the predominant influence of the aromatic character of organic molecules on the reactivity. The presence of such correlations constituted the first chemical evidence for the existence of two distinct catalytic sites, one responsible for the hydrogenation of the benzene ring, associated with an electron-withdrawing character, and the other responsible for the hydrogenolysis of the C, p2-X bonds, associated with an electron-donating character. The literature data concerning the hydroprocessing of substituted benzenes show that CoMo/AI203 and NiMo/A1203 catalysts behave differently. For example, the hydrodeoxygenation of methyl-substituted phenols proceeds mainly through hydrogenolysis of the CO bond over a sulfided CoMo/AI203 catalyst (3) and the authors concerned have also proposed that different active sites were responsible for the two reaction paths (see Fig. 1), one for CO bond cleavage and another for hydrogenation. Over a sulfided NiMo/AI203 catalyst, we have shown that the hydrodeoxygenation of phenols substituted by alkyl, cyclo-