Selective hydroxylation of benzene to phenol over supported vanadium oxide catalysts
Selective hydroxylation of benzene to phenol over supported vanadium oxide catalysts
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DOI：
10.1016/s0926-860x(02)00535-5
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发表时间：
2003-03
影响因子：
5.5
通讯作者：
K. Lemke;H. Ehrich;U. Lohse;H. Berndt;K. Jähnisch
中科院分区：
文献类型：
--
作者：
K. Lemke;H. Ehrich;U. Lohse;H. Berndt;K. Jähnisch
介绍了钒氧化物催化剂上苯与过氧化氢液相羟基化一步合成苯酚的研究。氧化钒催化剂已经使用MCM型的中孔硅质结构、Aerosil®300型的二氧化硅和无定形硅质微孔混合氧化物作为载体制备。催化剂的组成、比表面积和还原性的表征表明，钒氧化物物种高度分散在二氧化硅表面上。在广泛的筛选中，在不同的溶剂系统，如乙酸，丙酮，甲醇，乙腈以及在无溶剂的所谓的“三相”系统中测定催化性能。考察了催化剂中钒含量对羟基化反应的影响。在低钒含量（0.14wt.%）的VOx/SiO2催化剂上获得了最好的结果V）在作为溶剂的乙腈中。钒中心的分散性对催化剂性能的显著影响已被证明。
Investigations of the one-step liquid-phase hydroxylation of benzene to phenol by hydrogen peroxide on vanadium oxide catalysts are described. The vanadium oxide catalysts have been prepared using mesoporous siliceous structures of MCM-type, silica of Aerosil®300 type and amorphous siliceous microporous mixed oxides as supports. Characterization of composition, surface area, and reducibility of the catalysts showed that the vanadium oxide species were highly dispersed on the silica surfaces. In a broad screening, the catalytic performances were determined in different solvent systems such as acetic acid, acetone, methanol, acetonitrile as well as in the solvent-free so called “triphase” system. The influence of vanadium content of the catalyst on the hydroxylation was studied. Best results were obtained on a low vanadium-containing VOx/SiO2catalyst (0.14wt.% V) in acetonitrile as solvent. The drastic influence of dispersion of vanadium sites on the catalytic performance has been demonstrated.