Cu/MCM-41对苯羟基化为苯酚的催化作用

介绍了MCM - 4 1和Cu/MCM - 4 1的合成方法及Cu/MCM - 4 1对苯羟基化为苯酚的催化作用。即以正硅酸乙酯为硅源 ,十六烷基三甲基溴化铵为模板剂 ,氨水为碱性介质 ,在温度为 75℃的温和水热条件下 ,合成未脱除模板剂的MCM - 4 1中孔分子筛。产品在D/MAX -RB(日本理学 )衍射仪上经粉末X射线衍射进行表征。结果表明 ,在实验条件下经 8h反应 ,产品有较满意的结晶度和结构特征。在MCM - 4 1上直接采取等体积浸渍的方法 ,负载一定量的铜 ,得到一系列不同铜含量的Cu/MCM - 4 1催化剂。用双氧水作氧化剂 ,用合成的Cu/MCM -4 1作为催化剂 ,详细考察了催化剂用量、铜负载量、负载方法、溶剂、反应物摩尔比、反应温度、反应时间等因素对苯羟基化为苯酚的影响。反应产物通过GC - 340 0型气相色谱仪来分析。结果表明 ,在温度为 80℃ ,以乙腈为溶剂 ,0 .0 2 g铜质量分数为 5 %的催化剂 ,过氧化氢与苯的摩尔比为 1,反应时间为 4h的条件下 ,Cu/MCM - 4 1能有效催化苯羟基化为苯酚的反应 ,苯酚收率达 5 .8% ,且苯酚为唯一液相产品。

The Catalysis of Cu/MCM-41 for Hydroxylation of Benzene Into Phenol

The Si-MCM-41 has been successfully synthesized under a mild hydrothermal condition at 75 ℃ by using TEOS and CTMABr as the Si source and template respectively. The product was characterized by powder X-ray diffraction (XRD) in D/MAX-RB. The result shows that under the synthesis condition Si-MCM-41 has an excellent crystal structure. The preparation method of Cu/MCM-41 and the catalysis of Cu/MCM-41 for hydroxylation of benzene into phenol were investigated. By using Cu/MCM-41 as the heterogeneous catalyst and H 2O 2 as the oxidant, the authors discussed its effects on hydroxylation of benzene to phenol by observing catalyst dosage, its preparation method, solvents, reaction time, reaction temperature and other factors. It is concluded that Cu/MCM-41 can efficiently catalyze the oxidation of benzene into phenol, which is the one and only product, and the yield of phenol can get 5.8% under the reaction condition of 0.02 g catalyst,the mole ratio of n (H 2O 2)∶ n (benzene) =1, reaction temperature 80 ℃ and reaction time 4 h.