Elemental analysis of the clamshell, CS-CaO and surfactant treated
clamshell-derived Ca(OH)2 were determined using X-ray fluorescence
(XRF) spectrometer (Philips PWI404) equipped with a
scandium anode. In addition, organic matter content (%) was determined
using loss on ignition method [35,36]. The loss on ignition
(Loi) of the fresh clamshell was determined according to Loi
(%) = (Ai Af)/Ai 100, in which Ai is the weight of the dry sample
at 100 C and Af is the weight of the calcined sample at 300 C for
1 h. The crystallinity and chemical characteristic of all samples
were analyzed by using X-ray diffraction spectroscopy (XRD) from
Shimadzu diffractometer (model XRD-6000) employing Cu-Ka
radiation, 2h range from 10 to 80 at 30 kV and 30 mA generated
by Philips glass diffraction X-ray tube broad focus at 2 kW. Fouriertransform
infrared (FT-IR) band spectra were obtained using PerkinElmer
(PC) Spectrum 100 FTIR spectrometer in order to identify
surface functional groups of samples. Specific surface area and pore
distribution of the catalysts were obtained by BET nitrogen adsorption/desorption
analyzer (Thermo-Finnigan Sorpmatic 1990 series).
The morphology of the samples was observed using
scanning electron microscopy (SEM) (SEM JOEL 6400). Particle
sizes of hydration-surfactant treated samples were observed using
transmission electron microscopy (TEM) (Hitachi H-7100 TEM
with accelerating voltage of 10MV). Catalyst basicity and basic
strength distributions were studied by temperature-programmed
desorption (TPD) of CO2 using Thermo-Finnigan TPD/R/O 1100 series
apparatus which were equipped with thermal conductivity
detector.
3.