| 摘要 |
PURPOSE:To purify an exhaust gas and remove nitrogen oxide at high efficiency by removing nitrogen oxide from an oxygen-containing exhaust gas of an internal combustion engine by utilizing an exhaust gas purifying catalyst containing zeolite, cobalt, copper, an alkaline earth metal element, and a rare earth metal element. CONSTITUTION:Nitrogen oxides are removed from an oxygen-containing exhaust gas of an internal combustion engine by utilizing an exhaust gas purifying catalyst containing zeolite, cobalt, copper, an alkaline earth metal element, and a rare earth metal element. Nitrogen oxides are also removed from an oxygen-containing exhaust gas of an internal combustion engine by utilizing an exhaust gas purifying catalyst composed mainly of an aluminosilicate salt crystal having a formula WmZnO2n.SH2O{W stands for Na, Ca, K, Ba, and Sr; Z for Al+Si (Si/Al>1); n, m, and S is variable} and containing cobalt, copper, an alkaline earth metal element, and a rare earth metal element. As a result, nitrogen oxides are removed highly efficiently and thus the exhaust gas is purified. |
