马国富,张志芳.多孔管状氧化铝及其负载溴化铝的制备,表征及催化性能[J].分子催化,2011,(3):193-201 |
多孔管状氧化铝及其负载溴化铝的制备,表征及催化性能 |
Preparation, Characterization and Catalytic Properties of Porous Tubular Alumina Supported Aluminium Bromide |
投稿时间:2011-05-11 修订日期:2011-06-16 |
DOI: |
中文关键词: 棉花 模板合成 化学剪裁 Baeyer - Villiger氧化 |
英文关键词:Cotton Template synthesis Chemical tailoring Baeyer-Villiger oxidation |
基金项目: |
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中文摘要: |
应用棉花为模板,氯化铝为铝源,通过溶胶凝胶法制备了管状γ-氧化铝。通过化学剪裁制备了γ-氧化铝负载的溴化铝催化剂。采用高倍扫描电子显微镜,氮气吸附脱附和X射线衍射分析等技术对其形态,结构以及组成进行表征。实验表明,γ-氧化铝很好地复制棉花的多孔结构,经过化学剪裁,可以得到形态,结构和组分不同的γ-氧化铝负载的溴化铝催化剂。此催化剂成本低,环境友好,在Baeyer-Villiger氧化反应中,以30%的过氧化氢作为氧化剂,乙酸乙酯作为溶剂,70℃下,环己酮的转化率达到98%和环己内酯选择性达到100%。对部分的环酮和直连酮同样具有较高的催化活性。催化剂可以循环使用多次,活性没有明显的降低。 |
英文摘要: |
Tubular gamma alumina was prepared by sol-gel method using cotton as template and aluminium chloride as aluminum resource. Via chemical tailoring method, gamma alumina supported aluminum bromide was obtained. Several techniques such as high-resolution field-emission scanning electron microscopy, N2 adsorption techniques and X-ray diffraction were employed to investigate their morphology, structures as well as components. Experiments showed, via template synthesis, the gamma alumina fibers well replicated the nanoporous morphologies and hierarchical pore size of original cotton. After chemical tailoring, aluminum bromide was evenly distributed on the tubular alumina surface and pore. With different concentration of hydrobromic acid, the morphology, structure and component could be controllablly changed. These preparation methods made these catalysts exhibited unique characteristics, such as environmental friendship, low cost and non-toxicity. The Baeyer-Villiger oxidation reactions of ketones catalyzed by the gamma alumina supported aluminum bromide, together with 30% hydrogen peroxide as an oxidant, were carried out. The experimental results revealed that this type of reactions could proceed in ethylacetate at 70℃ with good yields and high regioselectivity, through an example of oxidized cyclohexanone. |
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