Methane dry reforming on Ni/Ce0.75Zr0.25O2-MgAl2O4 and Ni/Ce0.75Zr0.25O2-γ-alumina: Effects of support composition and water addition

Nickel catalysts (10wt.%) supported on MgAl2O4 and gamma-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), H-2-temperature programmed reduction (TPR) and CO2-temperature programmed desorption (TPD) were employed to observe the characteristics of the prepared catalysts. Ni/gamma-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 H-2/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 H-2/CO ratio. The CH4 conversions (and H-2/CO) increased to 81(1.1) with 0.5 water/carbon mole ratio in Ni/gamma-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 (Swt.%)-MgAl2O4 catalyst. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.