摘要
以不同金属离子交换的Y型分子筛(Me-NaY)为催化剂,对苯乙烯与氧气的环氧化反应进行了实验研究。采用XRD,BET对催化剂进行了表征,使用气质联用仪和气相色谱仪对产物进行了定性和定量分析。研究结果表明,Y型分子筛经离子交换后其基本骨架结构没有发生变化,反应的主要产物是环氧苯乙烷和苯甲醛。其中以Co2+交换Y型分子筛的活性最高。考察了各种条件对反应的影响,发现溶剂极性和粘度对反应的影响很大,低粘度极性溶剂对反应有利。升高反应温度能提高苯乙烯转化率,而环氧苯乙烷选择性呈下降趋势,反应时间为6 h反应已基本接近平衡。以Co2+交换Y型分子筛为催化剂,二甲基甲酰胺为溶剂,反应温度100℃,反应时间6 h的条件下,苯乙烯转化率达67.5%,环氧苯乙烷选择性达48.8%。
Using NaY zeolite （Me- NaY） ion - exchanged with various metal ions as catalysts, the cpoxidation of styrene with oxygen as oxidant was investigated. The catalysts were characterized by XRD and BET and the reaction products were qualitatively identified by GC MS and quantitatively analyzed by GC. The results show that the framework of NaY keeps unchanged after ion exchange, the main products of styrene epoxidation reaction are styrene oxide and benzaldehyde, and Co^2＋ exchanged zeolite Y exhibites the highest reaction activity. At the same time, various reaction conditions were examined by using Co^2＋ - exchanged zeolite Y as the catalyst. It is found that the viscosity and polarily of the solvent have strong influence on the reaction and the solvent with lower viscosity and weaker polarity is favorable, the conversion of styrene increases while the selectivity of styrene oxide decreases with the increase of the reaction temperature, the reaction reaches equilibrium for 6 h on the whole. Using Co^2＋ - exchanged zeolite Y as the catalyst and dimethyl formamide as the solvent, 67.5 % of styrene conversion and 48.8 % of styrene oxide selectivity are obtained at 1 000 T2 for 6 h.
出处
《石油化工高等学校学报》
EI
CAS
2006年第4期47-50,79,共5页
Journal of Petrochemical Universities
