铂纳米簇/N-己基化壳聚糖杂化膜催化苯加氢反应研究

对壳聚糖进行了N-己基化改性,并在此基础上制备了铂纳米簇/N-己基化壳聚糖杂化膜,研究了该杂化膜催化剂在苯加氢反应中的催化性能。利用FT-IR、TEM、XRD和XPS等手段对杂化膜催化剂的结构进行了表征。TEM结果显示,铂纳米粒子平均直径约为5 nm,XPS结果表明,Pt与壳聚糖中的N和O之间存在一定程度的配位。用N-己基化壳聚糖负载铂纳米簇杂化膜催化苯液相加氢反应,部分加氢产物环己烯的选择性可达60.3%,而单独以Pt纳米簇作为催化剂无壳聚糖膜时,没有环己烯生成。结合催化剂表征结果和催化性能分析,杂化膜在反应体系中的溶胀过程以及Pt与N、O之间的配位作用等因素是控制苯加氢反应的主要原因。

Hydrogenation of benzene catalyzed by Pt/N-C6H13-chitosan hybrid membrane

The functionalization of chitosan with n-hexaldehyde was done,and the corresponding Pt nano-cluster/N-C6H13-chitosan hybrid membranes were prepared.The catalytic properties for the liquid hydrogenation of benzene were investigated.TEM,FT-IR,XRD and XPS were used to characterize the structure of Pt nano-particles,N-C6H13-chitosan and Pt/N-C6H13-chitosan hybrid membrane.TEM results showed that the average size of Pt particles was about 5 nm,and Pt was coordinated with N and O in membrane to some extent.Compared with Pt/CS,the conversion of benzene catalyzed by Pt/N-C6H13-chitosan was gradually increased,and the selectivity of cyclohexene was increased firstly and then decreased giving a high selectivity for cyclohexene of 60.3%,with the increasing of the extent of substitution of —C6H13 in Pt/N-C6H13-chitosan.There was no cyclohexene in the product when the catalyst was only Pt nano-particles without chitosan hybrid membrane.So from the results,it could be seen that CS or N-C6H13-CS membranes played an important role in the controlling of benzene hydrogenation,and the relationship of the swelling degree and the catalytic property was discussed in detail.