An in situ XAS study on the incorporation of metal ions into AlPO4-5 framework in hydrothermal synthesis process
The in situ X-ray Absorption Spectroscopy (XAS) was employed to probe the incorporation of transition metal ions, such as Mn2+, Fe3+, Co2+ and Ni2+, from precursor gel to AlPO4-5 framework in hydrothermal synthesis process. With the crystallization, the number of coordinated oxygen around metal ions changes from 6 to 4, associated with a decrease in the coordination distance of metal ions to oxygen, as revealed by XAS. However, these metal ions are different in the incorporation behaviour and mechanism. The transition of Co2+ into the tetrahedral framework of AlPO4-5 is completed at 150 oC with the emergence of longrange ordered microporous structure, while the incorporation of Mn2+ and Fe3+ is much more difficult and starts after the build-up of microporous structure. On the other hand, the existence of Si4+ in the precursor gel has also considerable influences on the synthesis process.
Mei Dong Guofu Wang Zhangfeng Qin Jianguo Wang Tao Liu Yaning Xie Tiandou Hu
State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Science, P. Beijing Synchrotron Radiation Facility, Institute of High Energy, Chinese Academy of Sciences, Beiji
国际会议
北京
英文
2007-08-12（万方平台首次上网日期，不代表论文的发表时间）