| abstract |
(57) [Summary] [Structure] Three-way precious metal catalysts useful for the conversion treatment of pollutants in the fuel combustion gas emitted from automobiles or in the gas emissions from stationary fuel combustion sources are complex By utilizing an oxygen ion conductive support material, it has greatly improved chemical activity and thermal stability of the catalyst. The composite support comprises yttria, calcia, magnesia or scandia, and at least 40 wt% of an inert support material such as alumina or titania, 30 It has a surface area of ˜300 m 2 / g. The catalyst can be supported by a composite of yttria-stabilized zirconia (YSZ) and alumina, and can be composed of platinum or palladium as the major metal and minor metals rhodium or ruthenium dispersed on the support. 0. It contains from 01 to 3.0 wt% of all active metals. [Effect] This three-way catalyst is stable to heat, achieves a high level of removal of pollutants (CO, NO x , H 2 and hydrocarbons), and is capable of removing expensive noble active metals on the catalyst support material. It has a long catalyst life without the need for undesirably high loading. |