Pd/Hβ双功能催化剂上苯加氢烷基化合成环己基苯

Synthesis of Cyclohexylbenzene by Hydroalkylation of Benzene over Pd/Hβ Binary Catalyst

采用浸渍法制备了Pd/Hβ双功能催化剂,并用其催化苯加氢烷基化反应合成环己基苯,考察了反应温度、反应时间、氢气压力、载体的酸性和催化剂的金属担载量对反应的影响.结果表明,在2.5MPaH2、200℃和3h的条件下,苯的转化率为24.3%,环己基苯的选择性为88.0%.金属活性位与酸性位之间的平衡是苯加氢烷基化反应的关键.同时,探讨了苯的加氢烷基化反应机理.

The Pd/Hβ binary catalyst was prepared by the impregnation method and was used for the hydroalkylation of benzene to cyclohexylbenzene. The effects of reaction temperature, reaction time, hydrogen pressure, Hβ acidity, and metal loading were investigated. The results indicated that the conversion of benzene and the selectivity for cyclohexylbenzene approached 24.3 % and 88.0 %, respectively, under the conditions of 2.5 MPa H2, 200 ℃ , and 3 h. The preferable balance between metal active sites and acidic sites in catalyst was the key to the hydroalkylation of benzene. Moreover, the mechanism of the reaction was discussed.