Pre-reforming of liquefied petroleum gas over nickel catalysts supported on magnesium aluminum mixed oxides

A series of Ni/MgxAl catalysts with different Mg/Al molar ratios were prepared by impregnating Mg–Al mixed oxides with nickel nitrate aqueous solution and used for the pre-reforming of LPG in the temperature range of 400–500 °C. XRD and H2-TPR results showed that the Ni/MgxAl catalysts calcined at 800 °C mainly consisted of γ-Al2O3, Mg(Ni)Al2O4 and Mg(Ni)O phases varying with Mg/Al molar ratio without free NiO species observed. The effects of Mg/Al molar ratio, S/C molar ratio and reaction temperature on the catalytic behavior of the Ni/MgxAl catalysts were investigated in detail. The results revealed that the catalyst with Mg/Al molar ratio of 1.25 had the highest catalytic activity and stability. The increase in S/C molar ratio promoted both the steam reforming of LPG and the methanation of carbon oxides and hydrogen. The stability tests of 15%Ni/Mg1.25Al catalyst showed that the catalyst was stable for the pre-reforming of LPG, and the stability decreased with elevating the reaction temperature due to more coke deposition.