Reaction Engineering, Kinetics and Catalysts,
S. A. Hosseini
Volume 14, Issue 2 , 2017, , Pages 83-90
Abstract
Two Cu-Co and Co3O4 oxides were synthesized by the conventional sol-gel auto-combustion and their physical-chemical properties were characterized by XRD, FTIR, SEM, TPR and XPS. The XRD results indicated that copper-cobalt oxide appeared in a mixture form of Cu0.15Co2.85O4 spinel and CuO phases, whereas ...
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Two Cu-Co and Co3O4 oxides were synthesized by the conventional sol-gel auto-combustion and their physical-chemical properties were characterized by XRD, FTIR, SEM, TPR and XPS. The XRD results indicated that copper-cobalt oxide appeared in a mixture form of Cu0.15Co2.85O4 spinel and CuO phases, whereas the cobalt oxide exhibited in the pure form of Co3O4 spinel. The FTIR approved the formation of the spinel structure in the both samples. The SEM results showed that both oxides are as nanoparticles. Application of the same synthesis conditions for both samples let to obtain samples with different purity. The results of temperature program reduction (TPR) revealed that Cu-Co nano oxide is more reducible at lower temperatures. The copper-cobalt oxide exhibited the higher activity that the Co3O4 in catalytic combustion of toluene, which is explained by its higher reducibility at the reaction conditions and by a possible synergistic effect between Cu-Co oxide and CuO particles.
Reaction Engineering, Kinetics and Catalysts,
B. Izadkhah; D. Salari; A. Niaei; A. Tarjomannejad
Volume 14, Issue 1 , March 2017, , Pages 67-73
Abstract
In this paper, LaBO3 perovskite type catalyst formulations were prepared by sol-gel auto combustion method using citric acid as the fuel. Activity of catalysts was tested in catalytic oxidation of toluene as a model of volatile organic compounds. LaCoO3 perovskite formulation showed the highest activity ...
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In this paper, LaBO3 perovskite type catalyst formulations were prepared by sol-gel auto combustion method using citric acid as the fuel. Activity of catalysts was tested in catalytic oxidation of toluene as a model of volatile organic compounds. LaCoO3 perovskite formulation showed the highest activity among LaBO3 (Fe, Mn and Co) perovskite catalysts. So, LaCoO3 perovskite based catalyst was selected for further investigation and modification in order to improve catalytic activity. LaBO3 perovskite catalysts were modified by substitution of Co by Fe and Mn. The catalytic activity of LaCoO3 improved due to partial substitution of Co by Fe and Mn cations. LaCo0.7Mn0.3O3 showed the highest catalytic activity among the synthesized catalysts. The structures and morphology of synthesized perovskites were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The results of X-ray diffraction indicated that the LaBO3 and LaCo0.7B′0.3O3 samples obtained using sol-gel method had a pure perovskite-type crystal structure.