Method of purifying exhaust gas of internal- combustion engine

Abstract

Abstract PURPOSE:To improve exhaust-gas purifying performance, by activating a particular catalyst having oxygen storing function by shifting the atmosphere of exhaust gas to be passed through the catalyst between a rich side and a lean side according to a specific pattern. CONSTITUTION:Exhaust gas is passed through a ternary catalyst consisting of an inorganic porous carrier carrying palladium, at least one element of the platinum group other than palladium, and a base metal having oxygen storing function. The atmosphere of exhaust gas is kept at a lean side at least more than 5 seconds when it is necessary, for instance, at the time of accelerating an engine when a high load is acted to the engine, and shifted between a rich side and the lean side at least once in 5 seconds in ordinary operation of the engine. By such a method, it is enabled to prove the characteristics of purifying CO, HC and NOx as shown by a1, a2, a3 in the drawing.

Inventors

• 👤 Kazuhiko Shiratani
• 👤 和彦 白谷
• 👤 Shigenori Sakurai
• 👤 桜井　茂徳
• 👤 Yoshihiro Suzuki
• 👤 鈴木　喜博
• 👤 Satoru Sugawara
• 👤 悟 菅原

Bibliographic Details