Amorphous perovskite catalysts for nitrogen oxide reduction and methods of preparing the same

Abstract

The amorphous perovskite structure catalysts according to the present invention comprise a carrier material and a mixture of at least two metal oxides supported thereon, which have the following formula: (M.sup.1.sub.a O.sub.x.M.sup.2.sub.1-a O.sub.y)(M.sup.3.sub.b O.sub.z.M.sup.4.sub.1-b O.sub.w)/S wherein M.sup.1 and M.sup.2 independently of each other are selected from the group consisting of the lanthanide metals, the alkali metals and the alkaline earth metals, M.sup.3 and M.sup.4 independently of each other are selected from the group consisting of the transition metals and the platinum metals, a and b are from 0 to 1, x, y, z and w are determined stoichiometrically on the values of a and b, the ratio of ›M.sup.1 +M.sup.2 ! to ›M.sup.3 +M.sup.4 ! is 0.1.about.3.0:1.0, and S is a carrier material. The process for preparing the amorphous perovskite structure catalysts comprises dissolving completely at least two salt solutions of metals, M.sup.1, M.sup.2, M.sup.3 and M.sup.4, and an acid in an organic acid, preparing an ester type resin intermediate by adding a hydroxy alcohol to the solution, mixing the solution in a liquid state by adding a powder type carrier material, distilling the mixed solution under a reduced pressure so as to concentrate the solution into a high viscous state, drying the concentrated solution using a microwave into a gel type catalyst precursor, and calcining the precursor stepwise at the temperatures of 300.degree..about.700.degree. C. The process can provide amorphous perovskite structure catalysts having a high specific surface area and a good dispersion for denitrizing nitrogen oxides.

Dependencies are inferred from the claim text.