Solid-state Reaction and Benzene Removal Activities of Composite Powders in Ni-La-Al2O3 System

The Solid-state reaction, sintering and hydrocarbon-removal activities of composite powders in La-Ni-Al2O3 system were studied toward their application to heat-stable exhaust catalyst. The different routes with the impregnation technique were applied to prepare the composite powders. X-ray diffraction revealed the following solid-state reactions; γ-Al2O3 (+NiO) + La2O3 (500°C)→γ-Al2O3 (+NiO) + LaAlO3 (800-1000°C)→γ-Al2O3 (+NiO) + LaAlO3 + NiLaAl11O19 (1000-1100°C). The La-stabilization was effective to retain large surface areas of these composite powders. The C6H6 removal activities were compared for the Ni-La-Al2O3, heated at 800°C and 1000°C. The catalytic performance depended on microstructures in the La-Ni-A12O3 composite powders from different routes.