| 摘要 |
PURPOSE:To obtain a catalyst having excellent durability and low temp. activity to remove nitrogen oxides from oxygen-rich exhaust gas by constituting the catalyst of copper and solid acid produced by adding tungsten to zirconia and specifying the amts. of tungsten and zirconia of the compsn. CONSTITUTION:This catalyst to purify exhaust gas is used to remove nitrogen oxides and hydrocarbons from oxygen-rich exhaust gas containing nitrogen oxides, carbon monoxide, and hydrocarbons. The catalyst consists of copper and solid acid prepared by adding tungsten to zirconia, and the compsn. of the catalyst is 0.2-5.0mol% tungsten, 0.2-5.0mol% copper and 90-99.6mol% zirconia. Nitrogen oxides in oxygen-rich exhaust gas are removed by bringing the oxygen-rich exhaust gas containing nitrogen oxides, carbon monoxide and hydrocarbons into contact with the catalyst for purification of exhaust gas. The oxygen-rich exhaust gas to be purified is, for example, exhaust gas from an inner combustion engine such as of an automobile, especially in a large air-fuel ratio. |
