Abstract:

To reduce the effect of cordierite carrier on the activity and thermal stability of perovskites，LaMnO₃ monolithic catalysts with La₂O₃ and SiO₂ coating were prepared by in-situ deposition and slurry impregnation. The activity and thermal stability of the catalysts were investigated in catalytic combustion of toluene. It was shown that La and Mn oxides could be deposited uniformly and firmly on the surface of cordierite，but the active phases of LaMnO₃ perovskites could not be formed by in-situ deposition.  However the progress of slurry impregnation could maintain the structure and activity of LaMnO₃ catalyst. The monolithic LaMnO₃ showed the same catalytic performance as the pure LaMnO₃ powder catalyst. La₂O₃ coating was more effective than SiO₂ coating to keep high thermal stability and activity of LaMnO₃ on the surface of cordierite.