Article ID Journal Published Year Pages File Type
1275464 International Journal of Hydrogen Energy 2012 12 Pages PDF
Abstract

Nickel catalysts (10wt.%) supported on MgAl2O4 and γ-Al2O3 were prepared by the wet impregnation method and promoted with various contents of Ce0.75Zr0.25O2. X-ray diffraction (XRD), BET surface area, scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), H2-temperature programmed reduction (TPR) and CO2-temperature programmed desorption (TPD) were employed to observe the characteristics of the prepared catalysts. Ni/γ-Al2O3 and Ni/Ce0.75Zr0.25O2 (5wt.%)–MgAl2O4 showed better activity in CO2 methane reforming with 75.7(0.93) and 75.4(0.82) CH4 conversions (and H2/CO ratio). H2O was added to feed in the range of H2O/(CH4 + CO2): 0.1–0.5 to suppress reverse water gas shift (RWGS) effect and adjusting H2/CO ratio. The CH4 conversions (and H2/CO) increased to 81(1.1) with 0.5 water/carbon mole ratio in Ni/γ-Al2O3 and 85(1.2) with 0.2 water/carbon mole ratio in Ni/Ce0.75Zr0.25O2 (5wt.%)–MgAl2O4. The stability of Ni/Ce0.75Zr0.25O2 (5wt.%)–MgAl2O4 in the presence and absence of water was investigated. Coke formation and amount in used catalysts were examined by SEM and TGA, respectively. The results showed that the amount of carbon was suppressed and negligible coke formation (less than 3%) was observed in the presence of 0.2 water/carbon mole ratio over Ni/Ce0.75Zr0.25O2 (5wt.%)–MgAl2O4 catalyst.

► Nickel catalysts supported on MgAl2O4 and γ-Al2O3 were promoted with Ce0.75Zr0.25O2. ► Ni/γ-Al2O3 and Ni/Ce0.75Zr0.25O2 (5%wt.)–MgAl2O4 showed better activity in CO2 methane reforming.► H2O was added to feed to suppress reverse water gas shift effect and adjusting H2/CO ratio. ► The CH4 conversion and H2/CO increased in the presence of water. ► Ni/Ce0.75Zr0.25O2 (5%wt.)–MgAl2O4 showed good stability and negligible coke formation with water.

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Physical Sciences and Engineering Chemistry Electrochemistry
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