苯乙烯在酞菁钴分子筛催化下的环氧化反应

在相转移催化剂的协同作用下和溶剂 /水两相体系中 ,对在分子筛超笼中原位合成的酞菁钴催化剂(CoPC NaY)存在下的苯乙烯与次氯酸钠 (NaOCl)的环氧化反应进行了实验研究。采用GC MS联用仪和Varian34 0 0型气相色谱仪对环氧化产物进行了定性和定量分析。研究结果表明 ,在分子筛超笼中原位合成的酞菁钴 ,在溶剂 /水两相体系中对苯乙烯环氧化有一定的催化活性和选择性 ,苯乙烯环氧化的主要产物是苯基环氧乙烷和苯甲醛。在 5 5℃时 ,苯乙烯的转化率达到 5 4%,对苯基环氧乙烷的选择性达到 6 5 %。反应温度和氧化剂的加入量影响苯乙烯环氧化的转化率和苯基环氧乙烷的选择性 ,而反应时间只影响反应的转化率。在CoPC NaY催化苯乙烯与次氯酸钠的环氧化反应过程中 ,氧化剂 (OCl-)首先进入大分子化合物酞菁钴驻留的超笼中 ,将氧转移到酞菁钴催化剂上 ,形成一个高价的钴氧化物中间体 (OCoPC) ;然后苯乙烯在相转移催化剂的作用下通过相间扩散进入水相 ,并被分子筛吸附进入孔道 ,最后与钴氧化物中间体接触 ,此中间体将氧转移给苯乙烯 ,生成环氧化物。

Epoxidation of styrene over encapsulated cobalt phthalocyanine in supercage of Y zeolite

Taking the encapsulated cobalt phthalocyanine as catalyst, the epoxidation of styrene with sodium hypochloride taken as oxidizing agent was investigated in the system composed of solvent-water and in the presence of phase transfer catalyst. The epoxidized products of styrene were identified by GC-MS and analyzed by Varian 3400 gas chromatograph. The results indicate that the encapsulated cobalt phathalocyanine have certain catalytic activity and selectivity on the epoxidation of styrene. The main oxidates are benzyl epoxyethane and benzaldehyde. The reaction temperature, reaction time and the amount of oxidant have certain influence on the epoxidation of styrene. The reaction process of epoxidation for styrene includes two steps. Firstly, the oxidaizing agent has a reaction with the cobalt phathalocyanine and changed into an oxidative species. Secondly, the oxidative species oxidizes styrene and changes into benzyl epoxyethane.