Reaction Engineering, Kinetics and Catalysts,
P. Rashidi Zonouz; M.E. Masoumi; A. Niaei; A. Tarjomannejad
Volume 15, Issue 2 , May 2018, , Pages 91-102
Abstract
In this paper, catalytic oxidation of CO over the LaFe1-xCuxO3 (x= 0, 0.2, 0.4, 0.6) perovskite-type oxides was investigated. The catalysts were synthesized by sol-gel method and characterized by XRD, BET, FT-IR, H2-TPR and SEM methods. The catalytic activity of catalysts was tested in catalytic oxidation ...
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In this paper, catalytic oxidation of CO over the LaFe1-xCuxO3 (x= 0, 0.2, 0.4, 0.6) perovskite-type oxides was investigated. The catalysts were synthesized by sol-gel method and characterized by XRD, BET, FT-IR, H2-TPR and SEM methods. The catalytic activity of catalysts was tested in catalytic oxidation of CO. XRD patterns confirmed the synthesized perovskites to be single-phase perovskite-type oxides. The synthesized perovskite catalysts show high activity in the range of reaction temperature (50 - 300 ºC). The substitution of Cu in B-site of the perovskite catalysts enhanced their catalytic activity for CO oxidation. Among different synthesized perovskite catalysts, LaFe0.6Cu0.4O3 has the highest activity: nearly complete elimination of CO was achieved at 275 ºC with this catalyst. Kinetic studies for CO oxidation were performed based on power law and Mars-van Krevelen mechanisms. According to kinetic calculations, the most probable mechanism is the MKV-D (dissociative adsorption of oxygen) which can predict the experimental data with correlation coefficient of R2 > 0.995.
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.