Enhanced catalytic activity of Ni on η-Al2O3 and ZSM-5 on addition of ceria zirconia for the partial oxidation of methane

Nickel supported on Ti-Al2O3 and ZSM-5(80) catalysts with and without the addition of ceria-zirconia, were prepared by co-precipitation and wet impregnation methods and used for the low temperature catalytic partial oxidation of methane (CPOM). The catalysts were tested under reaction temperatures of between 400 and 700 degrees C with a WHSV of 63,000 mL g(-1) h(-1). The activity of the catalyst was found to be dependent on the support and preparation method. The optimum catalyst composition of those tested was 10% Ni on 25%CeO2-ZrO2/ZSM-5(80), prepared by co-precipitation, where the reaction reached equilibrium conversion at 400 degrees C (T-50 <400 degrees C), which is one of the lowest temperatures reported to date. Further increases in temperature led to improved selectivity to CO reaching 60% at 600 degrees C. Although the observed kinetics were found to be controlled by strong adsorption of CO at lower temperature, this was an equilibrium limitation with longer time on stream experiments showing no decrease in the catalyst activity over 25 hat 400 degrees C. (C) 2017 Elsevier B.V. All rights reserved.