反应控制相转移催化剂催化丙烯环氧化反应的影响因素  

Factors Affecting Propylene Epoxidation Catalyzed by Reaction-Controlled Phase-Transfer Catalyst

作　　者：金国杰[1] 杨红云[1] 陈皓[1] 高焕新[1] 谢在库[1] 

机构地区：[1]中国石油化工股份有限公司上海石油化工研究院,上海201208

出　　处：《催化学报》2005年第11期1005-1010,共6页

基　　金：国家重点基础研究发展计划项目(973计划)(2003CB615805)

摘　　要：以H2O2为氧化剂,以磷酸氢盐或磷酸二氢盐为添加剂,研究了反应控制相转移催化剂(磷钨杂多酸季铵盐)催化丙烯环氧化的反应性能.结果表明,当体系中不存在添加剂时,产物环氧丙烷的水解情况严重;加入适量的添加剂可有效抑制环氧丙烷的水解.作为抑制环氧丙烷水解的添加剂,磷酸氢盐比磷酸二氢盐具有更优异的性能,且磷酸氢钾比磷酸氢钠效果更佳.在没有丙烯的情况下,随着温度的升高,环氧丙烷水解反应加剧;在相同的温度下,环氧丙烷浓度越低,其水解率越高;当环氧丙烷浓度较低时,催化剂的存在促进其水解,但在较高的浓度下,催化剂的存在则可抑制其水解.随着温度的升高,H2O2分解反应加剧,当温度超过60℃时,分解速度显著加快.催化剂在油/水二相中的分配实验结果表明,在H2O2存在的情况下,于50℃达到平衡时,85.0%以上的催化剂被转移至有机相.The catalytic performance of a reaction-controlled phase-transfer catalyst, quaternary ammonium heteropolyphosphatotungstate, for propylene epoxidation was investigated using aqueous hydrogen peroxide as oxidant and HPO4^2- or H2PO4^- as additive. The product propylene oxide （PO） was hydrolyzed easily in the absence of the additive, while a proper amount of additive was added into the reaction mixture, the PO hydrolysis could be inhibited efficiently. For inhibiting the PO hydrolysis, HPO4^2- presented better properties than H2PO4^-, and K2HPO4 was more efficient than Na2HPO4. The hydrolysis rate of PO increased with increasing temperature without propylene; at the same temperature, the lower the PO concentration was, the higher its hydrolysis rate was. When the PO concentration was low, the presence of the catalyst facilitated the PO hydrolysis, but at the high PO concentration, the catalyst inhibited the PO hydrolysis. The decomposition rate of H2O2 increased with the increase in temperature, and a considerable amount of H2O2 was decomposed above 60℃. It was observed in the distribution test of the catalyst in oil-water two phases that more than 85.0 % of the catalyst was transferred into the oil phase at 50℃ in the presence of H2O2.

关 键 词：反应控制相转移催化剂 添加剂 过氧化氢 丙烯 环氧化 环氧丙烷 

分 类 号：O643.32[理学—物理化学]