Effect of composition and thermal pretreatment on properties of Ni-Mg-Al catalysts for CO2 reforming of methane

Ni-Mg-Al catalysts prepared by continuous coprecipitation were evaluated for carbon dioxide reforming of methane carried out between 500 and 700 degrees C. The mixed oxides obtained after calcination exhibit higher surface area values and lower crystallinity. The activity results obtained with different samples demonstrated that the catalytic properties of Ni-Mg-Al catalysts are more affected by the M-II/M-III ratio than the Ni/mg ratio. For samples with constant M-II/M-III ratio the best results were obtained for 5 >= Ni/Mg > 1 ratios. Among the thermal pretreatment effects, the reduction temperature was revealed as a strong influence on the activity and selectivity for the CO2 reforming of methane. In contrast, the catalytic properties can be considered practically independent from the calcination temperature, and the influence of this parameter is restricted to the decrease of the surface area values with the increase of the calcination temperature. (c) 2006 Elsevier B.V. All rights reserved.