Abstract:
This dissertation is dedicated to Experimental and Computational Studies of
Perovskite Oxygen Carrier Materials for CO2 Separation.Energy is basic need of this
hour. The combustion of natural sources like fossil fuels produce hazardous gases
like CO2. The concentration of CO2 in air is the main cause of depletion of ozone
layer and climate effects. To overcome this problem, Chemical looping combustion
CLC is a very promising technique. In this project, we synthesize perovskite oxygen
carrier materials for the separation of CO2.The proposed materials are Iron-based
strontium manganese oxide (FeSrMnO3), where (x = 0.1, 0.3, 0.5 , 0.7 , 0.9 ) are
prepared by using solid state reaction method. Different characteristics of perovskite
oxygen carrier materials FexSr1-xMnO3 are studied in this project like X-ray’s
diffraction (XRD), Raman spectroscopy, Fourier Transformation Infrared
Spectroscopy (FTIR), Thermogravimetric analysis (TGA), Scanning electron
microscopy (SEM) and some theoretical studies like Density Functional Theory
(DFT). The XRD pattern of (FeSrMnO3), where (x = 0.1, 0.3, 0.5, 0.7, 0.9 ) represents
the same pattern which is tetragonal with reference code JCPD NO: 00-051-1860.
The average crystalline size is 946, 765, 780 ,550 and 642 respectively. Raman
spectra of all samples FexSr1-xMnO3 show prominent bands at 132, 190, 432, 527,
648, 796, 895 and 980 cm-1
related to Fe-O vibration, symmetric stretching vibration
of metal oxygen chain of Mn-O-Mn O, symmetric and asymmetric stretching
vibration of Sr-O band, T2g mode, transverse, longitudinal and two phonons optical
(2LO) modes. FTIR spectra of all samples of FexSr1-xMnO3 show the peaks at 608,
770 – 900, 968, 1078, 1173, 1365 , 1491 , 3500-4000 cm-1 vibrational modes of Sr O, Mn-O stretching vibrations , Fe-O nanoparticles , vibrations among O-O bonding
and OH-functional group or the presence of adsorbed water molecules. Surface
morphology of prepared composite materials is studied by Scanning Electron
Microscopy (SEM) (homogenous and porous structure). The DFT calculations of
FexSr1-xMnO3 tells about the structure which shows both cubic and hexagonal, DOS
(Electronic Density of states) tells about the properties of metals and we can find
xiii
band gap of the material. The material shows metallic nature because no band gap
is observed in prepared oxygen carrier material
