文献类型：期刊文献

中文题名：稀土修饰Al_2O_3的表面积热稳定性

英文题名：Surface Area Stability of Aluminas Modified by Rare Earths

作者：赫崇衡[1];张文敏[1];汪仁[2]

机构：[1]安徽师范大学化学系,芜湖241000;[2]华东理工大学工业催化所,上海200237

年份：1996

卷号：12

期号：11

起止页码：971

中文期刊名：物理化学学报

外文期刊名：Acta Physico-Chimica Sinica

收录：CSTPCD;;Scopus;WOS:【SCI-EXPANDED(收录号:WOS:000207600400003)】；北大核心:【北大核心1992】；CSCD:【CSCD2011_2012】；PubMed;

语种：中文

中文关键词：稀土元素;氧化铝;比表面积;热稳定性;催化剂

外文关键词：Rare earths, Alumina, Surface area, Thermal stability

摘要：以不同稀土元素为添加剂，采用浸渍法和捏和法制备了γ－Al2O3样品,通过BET、XRD等手段，考察了在1273K湿空气中（含14kPa水蒸汽）,经不同时间处理γ－Al2O3的相变和烧结情况，比较了各样品水热烧结后比表面积的差异，并分析了产生这种差异的原因．探讨了Al2O3的高温水热烧结动力学．根据所得动力学参数，讨论了烧结机理，并计算了烧结速率.
Surface modification with rare earths was investigated for improving the hydrothermal stability of γ-Al2O3. The rare earths were added by impregnation or kneading method. Among the rare earths, studied lanthanum is the most effective promoter for inhibiting the reduction of surface area of Al2O3 sintered in wet air(14kPa water vapor) at 1273K for 24h, because its cations with valence 3+ and proper ionic radii can insert into the crystal lattice of Al2O3 and prevent the transition of Al2O3 from sintering and transforming to α-Al2O3. The presence of vapor-phase water in sinter tests was found to have a pronounced effect on surface area of Al2O3. The XRD measurements show that the α-phase increases and the crystal sizes become larger as area decreases. The kinetics for sintering of Al2O3 was studied and the constants, n and k, were used to calculate the rate of area loss at given area level.