Immobilization of metalloporphyrins into nanotubes of natural halloysite toward selective catalysts for oxidation reactions
Immobilization of metalloporphyrins into nanotubes of natural halloysite toward selective catalysts for oxidation reactions
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DOI：
10.1016/j.molcata.2007.12.009
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发表时间：
2008-03-18
影响因子：
--
通讯作者：
Nakagaki, Shirley
中科院分区：
文献类型：
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作者：
Machado, Guilherme Sippel;Dias de Freitas Castro, Kelly Aparecida;Nakagaki, Shirley
本文介绍了固定的阴离子和阳离子金属卟啉到纳米管/纳米卷的天然埃洛石，并调查这些新材料在有机底物的氧化催化活性。测试了两种金属卟啉固定化方法：在压力下固定化和在搅拌/回流条件下固定化。采用加压法固定的阴离子铁卟啉固定化率最高，为100%。阳离子铁（III）卟啉也以相对良好的产率固定到载体中，但对于中性铁（III）卟啉的固定没有获得令人鼓舞的结果。采用紫外可见光谱、红外光谱、X射线衍射、透射电镜等手段对材料进行了表征。以碘酰苯为氧供体，研究了完全固定化的铁卟啉在环辛烯、环己烷和正庚烷氧化反应中的催化活性。结果表明，这些新型固载化催化剂是一种很有前途的选择性氧化反应体系。(c)2007 Elsevier B. V.保留所有权利。
This paper describes the immobilization of anionic and cationic metalloporphyrins into the nanotubes/nanoscrolls of natural halloysite and investigates the catalytic activity of these novel materials in the oxidation of organic substrates. Two methods for metalloporphyrin immobilization were tested: immobilization under pressure and immobilization under stirring/reflux conditions. The best immobilization rate (100%) was obtained with the anionic iron(HI) porphyrin immobilized via the pressurized system. A cationic iron(Ill) porphyrin was also immobilized into the support with relatively good yields, but no encouraging results were obtained for the immobilization of a neutral iron(III) porphyrin. The obtained materials were characterized by UV-vis and infrared spectroscopies, X-ray diffraction, and transmission electron microscopy. The catalytic activity of a fully immobilized iron(III) porphyrin was evaluated in the oxidation of cyclo-octene, cyclohexane and n-heptane, using iodosylbenzene as the oxygen donor. It has been shown that these novel immobilized catalysts are a promising system for selective oxidation reactions. (c) 2007 Elsevier B.V. All rights reserved.