摘要
ZrO2在基载体Al2O3表面存在分散阈值(0.242 g/gAl2O3).在ZrO2/Al2O3复合载体中,ZrO2负载量不同其分布和粒度大小不同,当ZrO2负载量在0.242 g/gAl2O3-0.60 g/gAl2O3的范围内,ZrO2/Al2O3复合载体中纳米ZrO2的粒子的大小保持在4.2 nm,且单层分布在Al2O3的表面.当ZrO2负载量大于0.60 g/gAl2O3时,纳米粒子的粒径增大,并出现多层分布或堆积.XRD、DSC、HRTEM、XPS、H2-TPR结果表明,随着ZrO2负载量增大,复合载体中纳米ZrO2的分布由单层分布转化为多层或堆积分布,ZrO2负载量为0.60 g/gAl2O3时复合载体表面积最大(164.3 m2/g),ZrO2负载量的继续提高,复合载体的表面积明显下降.
There existed a dispersion threshold value （0. 242 g/gAl2O3 ） for the ZrO2 supported on Al2O3, which was similar to close-packed monolayer dispersion model. In the ZrO2/Al2O3 composite supports, the disparity in ZrO2 loading led to different distribution and particle sizes. When the ZrO2 loading amount was in the range of 0. 242 - 0. 60 g/gAl2O3, particle size was around 4. 2 nm with monolayer distribution on the surface of Al2O3, the particle size increased with multilayer distribution or packing form when the ZrO2 loading amount was more than 0. 60 g/gAl2O3. The results of XRD, DSC, HRTEM, XPS and H2-TPR showed that the distribution of ZrO2 in the composite supports changed from monolayer to multilayer or packing form. When the ZrO2 loading amount was at 0. 60 g/gAl2O3, the composite support had the maximal specific surface area（ 164. 3m^2/g） , and when the ZrO2 loading amount continued to increase, the specific surface area dropped markedly.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2007年第5期406-412,共7页
Journal of Molecular Catalysis(China)
基金
广西科学研究与技术开发计划课题(桂科攻0630004-1D)
高等学校博士点专项科研基金(20040304001)资助项目
