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 MIR 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.
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