分子印迹聚合物负载纳米金催化剂的制备及其底物识别性能  

Preparation of Molecularly Imprinted Polymer-Supported Gold Nanoparticles and Their Ability for Specific Substrate Recognition

作　　者：祝贞科[1] 谭蓉[1] 孙文庆[1] 银董红[1,2] 

机构地区：[1]湖南师范大学精细催化合成研究所,湖南长沙410081 [2]胡南中烟工业有限责任公司技术研发中心,湖南长沙410014

出　　处：《催化学报》2011年第9期1508-1512,共5页

基　　金：国家自然科学基金(20973057,21003044);湖南省自然科学基金(10JJ6028)~~

摘　　要：以4-硝基苯甲醇与氯金酸的络合物为模板,利用聚合物空腔内胺基捕获NaBH4还原的纳米粒子,设计和制备了一种具有底物识别性能的分子印迹聚合物负载纳米Au催化剂(Au/MIP).运用红外光谱、紫外-可见光谱和扫描电镜等方法对催化剂进行了表征.同时以水为溶剂,过氧化氢为氧化剂,考察了催化剂在取代苯甲醇氧化反应中的催化性能.结果表明,以Au/MIP为催化剂时,4-硝基苯甲醇转化率为75.6%,而以非印迹聚合物负载的纳米Au(Au/NIP)为催化剂时,4-硝基苯甲醇转化率仅为41.5%.以其它取代苯甲醇为底物时,Au/MIP与Au/NIP的催化活性差别不大.这说明Au/MIP催化剂活性与反应底物结构有关,脱除模板剂后它具有与4-硝基苯甲醇相匹配的空腔结构和识别位点,对反应底物表现出专一的识别性,因而提高了催化剂活性.A molecularly imprinted polymer-supported gold nanoparticle （Au/MIP） catalyst, which has the characteristics of specific substrate recognition, was prepared by the template complex of 4-nitrobenzyl alcohol （4-NBA） and hydrogen tetrachloroaurate（III）, where Au nanaoparticles were formed by the reduction with NaBH4 solution and captured by amino groups （-NH2） in the cavities of the MIP. The obtained samples were characterized with FT-IR spectroscopy, UV-Vis spectroscopy, and scanning electron microscopy. The catalytic activity and substrate recognition of the Au/MIP were investigated by the oxidation of substituted benzyl alcohol using H2O2 as the oxidant in water. It was found that the conversion of 4-NBA was up to 75.6% over Au/MIP when using the template molecule of 4-NBA as the substrate. However, the conversion of 4-NBA was only 41.5% over non-imprinted polymer-supported gold nanoparticle （Au/NIP） because no template molecule of 4-NBA was used in the preparation of catalyst. Furthermore, no significant difference of the catalytic activity between the catalysts Au/MIP and Au/NIP was observed when other substituted benzyl alcohols were used as the substrate. These results indicated that the catalytic activity of Au/MIP was related to the structure of substrates. The Au/MIP after removal of the template had molecular recognition shape and sites in the cavities matching to the substrate of 4-NBA molecule. The special recognizable cave of the Au/MIP exhibited unique substrate recognition and therefore improved the catalytic activity.

关 键 词：分子印迹聚合物 金纳米粒子 取代苯甲醇 催化氧化 底物识别性 

分 类 号：O643.32[理学—物理化学]