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以水为催化剂溶剂与原料乙苯组成液-液非均相体系,以NHPI结合CoSPc组成催化体系,在TBAB为相转移催化剂的作用下,对乙苯的氧化反应条件进行了研究.研究发现乙苯在该催化体系中的最佳氧化条件依次是:水油体积比为3∶1;n(TBAB)∶n(乙苯)=1∶40;n(NHPI)∶n(乙苯)=1∶10,n(NHPI)∶n(CoSPc)=24∶1,反应温度110℃,氧气压力0.75 MPa,搅拌速率350 rpm,反应时间0.5 h.在最佳反应条件下乙苯转化率为60.6%,苯乙酮的选择性为95.2%,1-苯乙醇的选择性为4.5%,产物总选择性达到了99.7%.在此基础上延长反应时间并不能提高乙苯的转化率,苯乙酮的选择性也会下降,研究发现NHPI的分解是乙苯转化率不随反应时间的延长而提高的原因,而苯乙酮的过度氧化为苯甲酸是产物选择性下降的原因.
Hydrolysis of ethylbenzene with NHPI and CoSPc as catalyst system was carried out by using water as catalyst solvent and ethylbenzene as raw material liquid-heterogeneous system. Under the action of TBAB as phase transfer catalyst, the oxidation conditions of ethylbenzene were studied. The optimum oxidation conditions of benzene in the catalytic system were as follows: the volume ratio of water to oil was 3:1; n (TBAB): n (ethylbenzene) = 1:40; n (NHPI): n The optimal reaction conditions were as follows: n (NHPI): n (CoSPc) = 24:1, reaction temperature 110 ℃, oxygen pressure 0.75 MPa, stirring rate 350 rpm and reaction time 0.5 h. , The selectivity of acetophenone is 95.2%, the selectivity of 1-phenylethanol is 4.5%, the total selectivity of the product is up to 99.7% .The extension of reaction time can not improve the conversion of ethylbenzene, acetophenone The selectivity of NHPI will also decrease. It is found that the decomposition of NHPI is the reason why the conversion of ethylbenzene does not increase with the reaction time. However, the over-oxidation of acetophenone to benzoic acid is the reason for the decrease of product selectivity.