Papers by Author: Kanit Soongprasit

Abstract: . La1-xCexCoO3 (x=0, 0.2, and 0.4) perovskite-type mixed oxides using polyvinyl alcohol (PVA) as complexing agent at two molar ratio of metal ion to PVA (1:1 and 1:2) were successfully prepared by sol-gel process. The precursor included lanthanum (II) nitrate hexahydrate, cerium (II) nitrate hexahydrate, and cobalt (II) nitrate hexahydrate where polyvinyl alcohol was added as complexing agent. The suitable condition of Cerium (Ce) substitution and PVA molar ratio were established for further application in hydrocarbon conversion to high value added products. TGA thermogram of as-prepared precursor showed that PVA absolutely decomposed at temperature higher than 500°C. XRD patterns of calcined catalyst showed both LaCoO3 rhombohedral and CeO2 cubic structures that confirmed the formation of mixed crystal structure. Nevertheless, Co3O4 slightly appeared with low peak intensity which came from the oxidation reaction of as-prepared catalyst during calcinations. XRD showed that PVA did not effect to crystal structure of synthesized catalyst. Higher PVA content added in the precursor cause the reduction of crystal growth of catalyst in calcinations step. In contrast, morphology of catalyst is directly related with PVA content such that the spongy and sheet-like structure were formed with increasing PVA content which prevented the agglomeration of particles. The results showed that PVA content play an important role in morphology of perovskite-type mixed oxide catalysts but did not affected to their crystal structures.

Abstract: Perovskite-type oxides catalyst are of interest for various application such as auto-thermal reforming (ART), catalytic wet air oxidation (CWOA) and piezoelectric (PZT). In this paper, La1-xCexNiO3 (x= 0-0.4) perovskite-type oxides have been prepared b sol-gel process using PVA. The precursor was mixed metal ion and PVA with a mole ratio of 1:1 and 1:2. The decomposition during the calcinations process was evaluated by thermogravimetric analysis and differential thermal analysis. Phase of synthesized materials were characterized with X-ray diffraction. Morphological analysis and elemental composition of catalysts was determined by Scanning electron microscope and energy dispersion spectroscopy. The characterization results show that highly crystalline and homogeneous phase of these perovskite oxides were successfully synthesized by the sol-gel method via PVA as a complexing agent.