CaO catalysts. Fourier transform infrared spectroscopy, FTIR analyzer
model IRAffinity – 1, Shimadzu spectrometer with the wave
number range in the region of 400 and 4000 cm1 was used for
investigating the structure and determination of the functional
group for the eggshell catalyst. Thermogravimetric analysis (TGA)
was used for characterizing thermal stability of the calcined CaO
samples by measuring changes in its physicochemical properties.
The TG analysis was measured by Shimadzu Simultaneous
TGA/DTA Analyzer DTG-60H. X-ray diffraction (XRD) analyses of
all the synthesized catalysts were carried out using a Shimadzu
diffractometer model XRD 6000. A Cu Ka radiation was used to
generate diffraction patterns at ambient temperature. The basic
strength of the catalysts was evaluated by temperatureprogrammed
desorption of CO2 (CO2-TPD) via the Thermo Finnigan
TPD/R/O 1100 series instrument.