物理化学学报 >> 2007, Vol. 23 >> Issue (03): 289-294.doi: 10.1016/S1872-1508(07)60021-7

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以无机铝盐为前驱体用溶胶凝胶法合成中孔氧化铝

郝志显;刘辉;郭彬;李红;张佳伟;甘礼华;徐子颉;陈龙武   

  1. 同济大学化学系, 上海 200092
  • 收稿日期:2006-08-10 修回日期:2006-10-19 发布日期:2007-03-07
  • 通讯作者: 郝志显 E-mail:haozhixian@mail.tongji.edu.cn

Sol-Gel Synthesis of Alumina Using Inorganic Salt Precursor

HAO Zhi-Xian;LIU Hui;GUO Bin;LI Hong;ZHANG Jia-Wei;GAN Li-Hua;XU Zi-Jie;CHEN Long-Wu   

  1. Department of Chemistry, Tongji University, Shanghai 200092, P. R. China
  • Received:2006-08-10 Revised:2006-10-19 Published:2007-03-07
  • Contact: HAO Zhi-Xian E-mail:haozhixian@mail.tongji.edu.cn

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摘要： 以水合硝酸铝(Al(NO3)3·9H2O)为前驱体, 通过乙醇介质中环氧丙烷的开环反应促使形成了透明的块状氧化铝凝胶. 凝胶在常压下干燥并于700 ℃焙烧后得到中孔无定型氧化铝. 通过改变环氧丙烷的加入量实现了氧化铝孔径和孔体积等宏观结构性能的调节. 用扫描电镜(SEM)、傅立叶变换红外光谱(FI-IR)和差热分析(DTA)等方法对样品进行了表征. 由于合成中存在环氧丙烷开环产物作为液体模板剂的造孔作用, 在氧化铝凝胶中造成了孔分布曲线具有双峰分布的墨水瓶状孔. 反应过程中pH值的测定和红外光谱的表征结果都证明环氧丙烷是一种很好的质子消耗剂, 其开环促使铝离子水解聚合并形成凝胶网络结构. 同时根据表征结果对环氧丙烷参与的溶胶凝胶氧化铝的合成机理进行了探讨.

关键词: 溶胶凝胶法, 介孔氧化铝, 环氧丙烷

Abstract: A simple procedure based on gelatification, promoted by the ring-opening reaction of propylene oxide, was proposed for the synthesis of alumina, in which hydrated aluminium nitrate (Al(NO3)3·9H2O) was mixed with propylene oxide and gelated in ethanol solvent. After being dried and calcined under air atmosphere, a kind of amorphous alumina with a well-defined mesopores structure was obtained. The samples were characterized by BET, SEM, FT-IR, and DTA. The results of liquid nitrogen adsorption indicated that two clear peaks appeared in the pore size distribution of each sample, whereas the larger pores were inkbottle-like. The average pore size of the alumina could be controlled by tuning the molar ratio of propylene oxide to aluminium nitrate over a range of pore diameters from 2.8 to 6.0 nm. The mechanism of the gelatification was finally proposed according to the characterizations. Both pH detection and FT-IR results demonstrated that propylene oxide indeed acted as an irreversible proton scavenger that induceed inorganic aluminium ions to undergo hydrolysis and condensation to form the aluminium oxide framework.

Key words: Sol-gel method, Mesoporous alumina, Propylene oxide