Speaker
Dr
Yingyot Poo-arporn
(Synchrotron Light Research Institute)
Description
Cerium-doped titanium dioxide was prepared by a sol-gel method using Titanium(IV)-isopropoxide and Ce(NO3)3•6H2O as the Ti and Ce precursors. X-ray absorption near edge structure (XANES) measurement was performed on the time-resolved XAS (Bonn-SUT-SLRI) beamline at Synchrotron Light Research Institute, Thailand. The beamline employs an energy dispersive monochromator and the position sensitive detector to record an XANES spectrum. For as prepared Ce/TiO2, XANES spectra show mainly the characteristic peaks due to the Ce3+. To monitor transition mechanism between Ce3+ and Ce4+ in Ce/TiO2, the in situ XANES measurements were performed. Ce L3-edge XANES spectra were recorded in 5 K intervals from 573 K to 823 K. Each spectrum was recorded at 250 ms with the averaging of 10 scans. At temperature lower than 763, there was no significant changes of whiteline peak. Two peaks corresponding to the CeO2 were clearly observed at 808 K. Although the calcinations temperature was increased to 823 K, there was no significant change in Ce L3-edge XANES spectra. This result indicated the sufficient temperature for CeO2 formation.
Keywords | Ce/TiO2, in situ XANES |
---|
Primary author
Dr
Yingyot Poo-arporn
(Synchrotron Light Research Institute)