含Bi中孔分子筛(Ⅱ) 苯乙烯氧化反应机理及条件的优化  

Bi-Si mesoporous zeolites(Ⅱ) Reaction mechanism and optimisation of reaction conditions in styrene oxidation

作　　者：陈晓晖[1] 苏建峰[1] 魏可镁[1] 

机构地区：[1]福州大学化肥催化剂国家工程研究中心,福建福州350002

出　　处：《化工学报》2005年第5期865-869,共5页CIESC Journal

基　　金：国家自然科学基金项目 (20306004);福建省青年科技人才创新项目( 2002J009 );福建省教育厅科技项目(JB02061)~~

摘　　要：以十六烷基三甲基溴化铵为模板剂, 正硅酸乙酯为硅源, 硝酸铋为铋源, 在弱碱性的条件下用水热法合成了Bi Si中孔分子筛, 该分子筛在苯乙烯催化氧化制苯甲醛的反应中具有很好的催化活性. 通过改变溶剂的种类及用量、反应时间、反应温度、双氧水浓度、催化剂用量, 获得了较佳反应条件, 结果表明: 在以25 ml甲醇为溶剂, 以4 5 ml H2O2 (30%) 为氧化剂, 苯乙烯用量1 5 ml, 催化剂用量0 075 g, 80℃反应2 h的条件下, 苯乙烯转化率43 1%, 苯甲醛选择性73 5%, 苯甲醛产率达到31 7%, 同时对可能的苯乙烯氧化反应机理进行了推测.Bi-Si mesoporous molecular zeolites(Bi-Si) was synthesized by the hydrothermal method with ethyl silicate (TEOS)as silica source, Bi(NO_3)_3·5H_2O as Bi source, and cetyltrimethylammonium bromide(CTAB)as template. Bi-Si catalyst had high ordering structures and high reaction activity in oxidation of styrene with hydrogen peroxide to benzaldehyde. The effects of solvents, reaction time, reaction temperature, oxidant concentration and Bi-Si concentration on the oxidation of styrene to benzaldehyde were studied systematically. It was found that in the following reaction conditions: catalyst 0.075 g, styrene 1.5 ml, methanol 25 ml,H_2O_2(30%) 4.5 ml, T =80 ℃, t =2 h,the conversion of styrene was 43.1%, the selectivity to benzaldehyde was 73.5%,the yield of benzaldehyde reached 31.7%.The possible reaction mechanism could be that one styrene molecule reacted with two H_2O_2 molecules on two joined catalytically active sites.

关 键 词：中孔分子筛 氧化 苯乙烯 苯甲醛 反应机理 

分 类 号：O643[理学—物理化学] TQ426[理学—化学]