Liquid-phase oxidation of benzene to phenol by CuO–Al2O3 catalysts prepared by co-precipitation method
Liquid-phase oxidation of benzene to phenol by CuO–Al2O3 catalysts prepared by co-precipitation method
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DOI：
10.1016/s1381-1169(01)00242-4
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发表时间：
2001-11
影响因子：
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通讯作者：
T. Miyahara;H. Kanzaki;Rei Hamada;S. Kuroiwa;S. Nishiyama;S. Tsuruya
中科院分区：
文献类型：
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作者：
T. Miyahara;H. Kanzaki;Rei Hamada;S. Kuroiwa;S. Nishiyama;S. Tsuruya
在醋酸水溶液中，采用负载铜催化剂，在温和反应条件下，对苯进行了液相催化氧化直接制苯酚的研究。气态氧和抗坏血酸分别用作氧化剂和还原剂。在所研究的负载型Cu催化剂中，浸渍法制备的Cu催化剂，无论采用何种氧化物载体，在苯氧化过程中，Cu都有明显的浸出现象。用Cu(NO3)2·3H2O和Al(NO3)3·9H2O共沉淀法制备的负载型Cu催化剂（CuO-Al2O3）与用Al2O3、SiO2、MCM-41等浸渍法制备的负载型Cu催化剂（CuO-Al2O3）相比，对Cu的浸出有抑制作用。以cuo - al2o3为催化剂，考察了负载Cu量、O2分压、抗坏血酸用量、溶剂中乙酸浓度和反应温度对苯酚产率的影响。含水溶剂包括高浓度醋酸(约80vol。%)显著抑制了Cu在cuo - al2o3催化剂中的浸出。在CuO-Al2O3催化苯氧化过程中检测到H2O2，认为H2O2在苯酚生成中起重要作用。
The liquid-phase catalytic oxidation of benzene to directly produce phenol was attempted under mild reaction conditions using supported Cu catalysts in aqueous acetic acid solvent. Gaseous oxygen and ascorbic acid were used as an oxidant and a reductant, respectively. Among the supported Cu catalysts studied, the Cu catalysts prepared by the impregnation method, irrespective of the oxide supports, the Cu species were considerably leached during the benzene oxidation. A supported Cu catalyst (CuO–Al2O3) prepared by co-precipitation of Cu(NO3)2·3H2O and Al(NO3)3·9H2O inhibited the leaching of Cu species in comparison with the Cu catalysts supported by the impregnation method on Al2O3, SiO2, MCM-41, etc. The influences of the amount of supported Cu, the partial pressure of O2, the amount of ascorbic acid, the concentration of acetic acid in the solvent, and the reaction temperature on the phenol yield were investigated using the CuO–Al2O3catalyst. The aqueous solvent including high concentration of acetic acid (around 80vol.%) dramatically inhibited the leaching of Cu species in the CuO–Al2O3catalyst. H2O2, which is considered to play an important role in phenol formation, was detected during the benzene oxidation catalyzed by CuO–Al2O3.