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,
N. Hoshyar; A. Irankhah Irankhah; M. Jafari
Volume 12, Issue 3 , July 2015, , Pages 3-14
Abstract
e"> The CeMnO2 supports were prepared via co-precipitation method by ammonia as precipitating agent. The CuO/CeO2 and CuO/Ce(1-x)MnxO2 (x=0.1, 0.3 and 0.5) catalysts were synthesized by wet impregnation method. The physicochemical properties of the prepared CuO/Ce(1-x)MnxO2 catalysts were characterized ...
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e"> The CeMnO2 supports were prepared via co-precipitation method by ammonia as precipitating agent. The CuO/CeO2 and CuO/Ce(1-x)MnxO2 (x=0.1, 0.3 and 0.5) catalysts were synthesized by wet impregnation method. The physicochemical properties of the prepared CuO/Ce(1-x)MnxO2 catalysts were characterized by N2 adsorption-desorption, powder X-ray diffraction (XRD) and programmed H2 temperature reduction (H2-TPR). The effects of Cu and Mn loading were investigated on the catalytic performance. The findings illustrated that the 7% CuO/Ce0.9Mn0.1O2 catalyst shows high activity for CO-PrOx. The high activity of 7% CuO/Ce0.9Mn0.1O2 catalyst was ascribed to high surface area of the support, synergetic effects of CuO and CeO2 and increases of the mobility of lattice oxygen in ceria by addition of MnO2. The effects of presence of H2O in the reaction feed stream, oxygen to CO ratio (λ) and gas hourly space velocity (GHSV) on the catalytic activity of 7% CuO/Ce0.9Mn0.1O2 were evaluated. It was found that the best performance of 7% CuO/Ce0.9Mn0.1O2 catalyst was obtained at λ=2, GHSV=20000 h-1 and in addition, the presence of H2O had negative effects on the activity of the catalyst. In the long term stability test, nearly 100% CO conversion was maintained for 50 h at 120°C with 70-80% CO2 selectivity.