| abstract |
Perovskite-type catalyst consists essentially of a metal oxide composition and methods of using them are provided. The metal oxide composition is represented by the general formula A a−x B x MO b , in which A is a mixture of elements originally in the form of single phase mixed lanthanides collected from bastnasite; B is a divalent or monovalent cation; M is at least one element selected from the group consisting of elements of an atomic number of from 23 to 30, 40 to 51, and 73 to 80; a is 1 or 2; b is 3 when a is 1 or b is 4 when a is 2; and x is a number defined by 0≦x<0.5. Methods of making and using the perovskite-type catalysts are also provided. The perovskite-type catalyst may be used to reduce nitrogen oxides, oxidize carbon monoxide, and oxidize hydrocarbons in an exhaust stream from a motor vehicle. Methods of such a use are provided. |