固载型Cosalen/NaY催化剂在环己烷氧化中的催化性能

采用“Ship-in-a-Bottle”技术制备了NaY分子筛固载型N,N′-双水杨醛叉乙二胺合钴(Cosalen)配合物(Cosalen/NaY)。傅里叶变换红外光谱、紫外-可见光谱、X射线衍射、比表面积测定、扫描电镜测试结果表明,配合物Cosalen已成功地封装在NaY分子筛的超笼内,且封装过程对NaY分子筛载体的结构没有破坏作用。在以氧气为氧源的环己烷氧化反应中,Cosalen/NaY催化剂具有较好的活性和对环己醇、环己酮、己二酸的选择性。该催化反应体系不存在明显的诱导期,且产物中环己基过氧化氢(CHHP)的选择性很低,表明Cosalen/NaY催化剂能加速CHHP的分解。以乙腈为溶剂,在初始氧气压力0.80M Pa、130℃下反应3h,环己烷的转化率达到24%以上。实验还发现,Cosalen/NaY催化剂具有将环己烷一步氧化为己二酸的潜力,而且在使用过程中没有明显的活性组分流失,可重复使用。

Performance of Cosalen/NaY Catalyst Supported Catalyst in Cyclohexane Oxidation

N,N′-bis(salicylidene)ethylenedimino cobalt(Cosalen)was encapsulated on NaY molecular sieve by"Ship-in-a-Bottle"method.The obtained Cosalen/NaY was used as catalyst for cyclohexane oxidation and was characterized by means of FTIR,UV-Vis,XRD,SEM and surface areas analysis.Structure of NaY molecular sieve did not change in encapsulation process.It showed better activity and selectivity to cyclohexanol,cyclohexanone and adipic acid than the sole Cosalen.There was no obvious induction period during oxidation.Only small amount of cyclohexyl hydroperoxide(CHHP)analyzed in products indicated that Cosalen/NaY catalyst was able to accelerate decomposition of CHHP.Effects of initial oxygen pressure,temperature and time on oxidation were investigated.Conversion of cyclohexane could reach 24% at 130℃ for 3h under initial oxygen pressure 0.80MPa.Cosalen/NaY catalyst had the potential catalytic ability for oxidization of cyclohexane into adipic acid.The catalyst had been reused three times.