Preparation and Characterization of Magnetoplumbite Oxides CaNi_y Al_12-y O_19-δ

A series of magnetoplumbite oxides CaNi_y Al_12-y O_19-δ（y=0.3,0.6, 0.9, 1.0） were prepared and characterized using XRD, XPS, TPR and TGA techniques. The results showed that the series of oxides CaNi_y Al_12-y O_19-δ exhibited almost the same crystal structure and similar reduction stability. A pare magnetoplumbite oxides CaNi_y Al_12-y O_19-δ phase could be formed only when y value is at 0＜y≤1. The reduced oxides CaNi_y Al_12-y O_19-δ exhibited significant catalytic activities and stability during the reaction of CO₂ reforming of methane to synthesis gas at 780 ℃, no deactivation due to a little carbon deposition was found. The catalytic activitis were obviously affected by the modifier Ni in the lattices, under the same reaction condition, the conversions of CH₄ and CO₂ increased with an increase in the amount （y value）of the modifier Ni.