Hydrogenation of Phenylethanol and Acetylcyclohexane over Pt
Hydrogenation of Phenylethanol and Acetylcyclohexane over Pt
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苯乙醇和乙酰环己烷在 Pt 上的氢化
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
M. Vannice
中科院分区：
文献类型：
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作者：
D. Sanders;S. Lin;M. Vannice
当存在不饱和C[双键]C键和羰基时，控制分子内选择性具有商业重要性。第VIII族金属，特别是Ni和Pt，用于取代芳族烃，亚铬酸铜催化剂通常用于取代芳族分子中的羰基，因为它们对于氢化芳环相对无活性。作者最近研究了苯乙酮（C[sub 6]H[sub 5]COCH[sub 3]）在Pt催化剂上的加氢反应，测定了苯基乙醇（C[sub 6]H[sub 5]CHOHCH[sub 3]）生成与乙酰基环己烷（C[sub 6]H[sub 11]COCH[sub 3]）生成的相对论速率，并考察了载体对产物选择性的影响。在典型的Pt催化剂如Pt/SiO[sub 2]和Pt/[eta]-Al[sub 2]O[sub 3]上，即使转化率高达50%，苯乙醇也占产物的约60-70摩尔%;然而，使用TiO[sub 2]作为载体使选择性转变为90%或更高。在该反应网络中可能有许多产物，并且存在两个主要考虑因素来解释对PhEt的高选择性，特别是在高苯乙酮转化率下-各种化合物的固有氢化速率或它们在反应条件下的相对表面覆盖率，即，竞争吸附为了了解这两个因素中的哪一个在该反应体系中占主导地位，在Pt上研究了苯基乙醇（PhEt）和乙酰基环己烷（AcCy）的气相氢化，并与苯乙酮（AcPh）氢化速率进行了比较。PhEt和AcCy在Pt上的氢化都没有研究过;因此，这里报道了这些反应的第一个比活性。参考文献6篇，图3，3个标签。«少
The control of intramolecular selectivity when both unsaturated C[double bond]C bonds and carbonyl groups are present is of commercial importance. Group VIII metals, particularly Ni and Pt, are used to hydrogenate aromatic hydrocarbons, and copper chromite catalysts have routinely been used to hydrogenate carbonyl groups in aromatic molecules as they are relatively inactive for hydrogenating aromatic rings. The authors have recently studied acetophenone (C[sub 6]H[sub 5]COCH[sub 3]) hydrogenation over Pt to determine the relativistic rates of phenylethanol (C[sub 6]H[sub 5]CHOHCH[sub 3]) formation versus acetylcyclohexane (C[sub 6]H[sub 11]COCH[sub 3]) formation and to examine the influence of the support on product selectivity. Phenylethanol constituted about 60-70 mole% of the product over typical Pt catalysts such as Pt/SiO[sub 2] and Pt/[eta]-Al[sub 2]O[sub 3], even at conversions up to 50%; however, the use of TiO[sub 2] as a support shifted the selectivity to 90% or higher. There are numerous products possible in this reaction network, and two major considerations exist to account for the high selectivity to PhEt, especially at high acetophenone conversions-the intrinsic hydrogenation rates of the various compounds or their relative surface coverages under reaction conditions, i.e., competitive adsorption. To see which of these two factors is predominant in this reaction system,more » the vapor-phase hydrogenation of phenylethanol (PhEt) and acetylcyclohexane (AcCy) was studied over Pt and compared to acetophenone (AcPh) hydrogenation rates. Neither PhEt nor AcCy hydrogenation over Pt has been studied; consequently, the first specific activities of these reactions are reported here. 6 refs., 3 figs., 3 tabs.« less