摘要
采用石墨坩埚,通过25 kg真空感应炉熔炼制备铈-镧稀土碳化物,然后在室温下水解铈-镧稀土碳化物后制得比表面积为131 m^2/g的镧掺杂CeO_2纳米粉。经过不同温度热处理(600℃~1000℃)的镧掺杂CeO_2纳米粉的X射线衍射、激光拉曼光谱、透射电子显微镜及其甲烷催化燃烧反应等结果表明,镧离子替代CeO_2晶格中的部分铈离子形成铈镧固溶体,与相同工艺制备的纯CeO_2纳米粉相比,La的掺杂不仅使CeO_2纳米粉热稳定性有所提高,而且还具有良好的甲烷催化氧化性能。此方法是一种可大规模制备稀土元素掺杂于CeO_2纳米粉的有效方法。
The Cerium lanthanum carbides were prepared in 25 kg vacuum induction melting furnace. La - doped CeO2 nanopowders were prepared by hydrolysis and oxidation of cerium lanthanum carbide at room temperature. The BET surface ar- ea of the La- doped CeO2 nanopowders reached 131 m2/g. Those nanopowders were heat treated at different temperatures in order to improve their catalytic activities. And the microstructures and structure - activity relationship in methane combustion catalysis were investigated by X -ray diffraction （XRD）, Raman spectroscopy and transmission electron microscopy （TEM）. In this strategy, the lanthanum ions were used to partially replace the cerium ions of the CeO2 lattice, forming a solid solution of cerium lanthanum. Compared to the pure CeO2, the thermal stability of La - doped CeO2 is increased due to the lanthanum doping. The La - doped CeO2 nanopowders also have a good ca4 catalytic performance. It is an effective method for the mass - production of rare earth elment - doped CeO2 nanopowders.
出处
《稀土》
EI
CAS
CSCD
北大核心
2017年第4期30-37,共8页
Chinese Rare Earths
基金
国家自然科学基金项目(U1531120)
上海市自然科学基金(13ZR1415300)
关键词
铈镧碳化物
镧掺杂CeO2纳米粉
水解氧化
甲烷催化性能
cerium lanthanum carbides
La - doped CeO2 nanopowders
hydrolyzed - oxidized
CH4 catalytic performance
