摘要:
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以十六烷基三甲基溴化铵(cetyltrimethylammonium bromide,CTAB)为模板剂,正硅酸乙酯(tetraethl orthosilicate,TEOS)为二氧化硅源,在酸性条件下加入BiCl3和H3BO3制备了(Bi,B)/SBA(SBA为以学校名称Santa Barbara命名的一种材料)-3介孔氧化硅复合材料。X射线衍射和高分辨率透射电镜结果表明:复合介孔材料具有六方排列的孔道结构;通过N2吸附曲线可知复合介孔材料具有极高的比表面积,孔径主要集中分布在2.4 nm左右;从Fourier红外光谱位于966 cm-1和1 384 cm-1的吸收峰可知,元素B在孔壁中以四配位和三配位的形式存在;从差热分析曲线可看到,随着B,Bi的掺入,在478℃附近出现了不同的放热峰。实验结果表明:由于B,Bi的掺杂不仅在纯的SBA-3的介孔材料中引入了BrΦnsted酸中心,并且进一步改善了材料的有序性和热稳定性。
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Mesoporous composite material of (Bi,B)/SBA - 3 (a material named by the uiversity of Santa Barbara, SB A) was synthesized by using cetyltrimethylammonium bromide(CTAB)as template and tetraethyl orthosilicate(TEOS)as silicon source with the addition of other chemicals such as BiCl3 and H3 BO3. Examination results indicate that the material prepared has a periodic hexagonal structure by X-ray diffraction and high-resolution transmission electron microscopy. The results of N2 adsorption show that the material has a very high specific surface area with pore channel size of about 2. 4 nm. Form the endothermic peak of FTIR at the bands of 966 cm-1 and 1 384 cm-1 it is found that boron element exists in the form of the tetracoordinated and tricoordinated on the framework. A new exothermal peak is found on DTA cure at nearly 478 ℃ when bismuth and boron are added. The experimental results reveal that it not only introduces Br nsted acid sites but also improves the hydrothermal stability and long range order of the material after doping bismuth and boron.my husband cheated on me click here women who cheat on husband cialis discount coupons go cialis 2015 coupon
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基金项目:
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国家自然科学基金(90206017);;上海市纳米中心及AM基金资助项目
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作者简介:
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参考文献:
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