摘要
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.
Water was inducted as a solvent of catalysts in the oxidation of ethylbenzene catalyzed by a combined catalytic system consisting of NHPI and CoSPc, promoted by phase transfer catalyst TBAB. The present of water formed a liquid-liquid heterogeneous system, in which, the most favorable reaction conditions were optimized, Ex- perimental results showed that the reaction conditions of controlling the volume ratio of water to ethylbenzene to be 3 ： 1, the molar ratio of TBAB to ethylbenzen to be 1：40, n（NHPI） ： n（Ethylbenzene） = 1 ： 10, n（NHPI） ： n（CoSPc） = 24 ： 1, temperature = 110℃, stirring rate 350 rpm, O2 pressure 0.75 MPa, reaction time 0.5 h were the most favorable, under which the conversion of ethylbenzene reached 60.6% , the selectivity of acetophe- none and 1-phenylethanol reached 95.2% and 4.5% , respectively, and total products selectivity reached 99.7%. The conversion of ethylbenzene could not be improved by prolonging reaction time, otherwise, the selectivity of ace- tophenone decreased, empirical results indicated that the decomposition of NHPI took the blame of negative results in the improving of ethylbenzene conversion, the selectivity decrease of acetophenone was the consequence of its＇ over oxidation.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2013年第1期16-22,共7页
Journal of Molecular Catalysis(China)
基金
中央高校基本科研业务费专项资金(14CX02008A)
山东省自然科学基金(2009ZRA05107)
关键词
N-羟基邻苯二甲酰亚胺
磺化酞菁钴
分子氧氧化
乙苯氧化
非均相氧化
N-hydroxyphthalimide
cobalt sulfonated phthalocyanine
aerobic oxidation
ethylbenzene oxidation
heterogeneous oxidation
