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耐高温高表面氧化铝的制备及性质──添加钡及钡与镧的协同作用对氧化铝热稳定性的影响
Preparation and Property of High Surface Area Alumina Resisting High TemperatureEffect of Barium Addition and Its Synergy with Lanthanum on the Thermal Stability of Alumina
【摘要】 <正>氧化铝是高温催化反应中常用的载体材料.高于1000℃时,Al2O3 通过表面活性原子的迁移和表面羟基脱水发生烧结,并向α相转变[1,2],同时随着比表面积剧烈下降,导致催化剂活性组分聚集,催化剂活性下降等.大量研究表明,稀土元素,硅及碱土元素可明显改善氧化铝的热稳定性[3-8].本文以溶胶-凝胶法单独引入Ba元素,考察了Ba添加量对Al2O3热稳定性的影响.还采用溶胶-凝胶与表面浸渍相结合的方式共同引入La和Ba,考察了两元素协同作用对Al2O3 热稳定性的影响.
【Abstract】 Abstract High surface area alumina resisting high temperature was prepared by sol-gel method or sol-gel assisted impregnation method. The effects of barium addition and its synergy with lanthanum on the thermal stability were studied by XRD and surface analysis techniques. The results showed that when Ba was introduced by sol-gel method, Ba showed a little effect in improving the thermal stability of alumina. While 5. 2%La introduced by sol-gel method and 2. 0%Ba was introduced by impregnation method, because of the synergy between barium and lanthanum, the alumina maintained surface area of 112. 90 m2/g after calcination at 1 100 for 32 h.
- 【文献出处】 高等学校化学学报 ,Chemical Research In Chinese Universities , 编辑部邮箱 ,2002年05期
- 【分类号】O643.3
- 【被引频次】31
- 【下载频次】408