不同取代度纤维素苯甲酸酯负载铂催化苯加氢

以N,N-二甲基乙酰胺/氯化锂(DMAc/LiCl)为溶剂溶解纤维素,吡啶(Py)为催化剂,苯甲酰氯为酯化剂在均相条件下进行酯化反应,通过控制苯甲酰氯的量得到了不同取代度(DS)的纤维素苯甲酸酯(CB),溶胀测试结果表明不同取代度的CB在苯、环己烯和环己烷中的溶胀度不同。将微波还原得到的铂纳米簇与CB杂化后得到Pt/CB杂化膜,并将其用于苯催化加氢反应中。利用FT-IR、XPS、XRD、DSC和TEM对不同取代度的CB和杂化膜的结构与性能进行了表征。研究发现膜的溶胀度直接影响苯的转化率和环己烯的选择性,活性评价结果显示,苯的转化率随着取代度的增大而增大,最高为7.29%;环己烯的选择性随取代度的增大而减小,最高为0.43%。

Cellulose Benzoyl Ester with Different Substitution Degree Supported Pt Catalyst for Benzene Hydrogenation

Cellulose benzoyl ester（CB） was synthesized with benzoyl chloride as the esterifying agent under homoge- neous conditions （cellulose was dissolved in DMAc/LiC1） in presence of pyridine （Py） as catalyst. Different substitution degree CBs were obtained by controlling the amount of benzoyl chloride, and the resulting CBs had different swelling de- gree in benzene, cyclohexene and cyclohexane. Hybrid membrane, used for the selective hydrogenation, was prepared by supporting Pt nano - clusters （ obtained by refluxing reduction by microwave） into CB. FT - IR, XRD, XPS and TEM were applied to characterize the CBs and the hybrid membranes. Research results demonstrated that swelling behavior ac- ted as a crucial factor to the conversion of benzene and selectivity of cyctohexene. Active evaluation results indicated that the conversion of benzene （ highest, 7.29% ） increased while the selectivity of cyclohexene （ highest, 0.43% ） decreased with the increasing of CBs substitution degree.