文件类型:PDF文档
文件大小:81K
PROBLEM TO BE SOLVED : To produce a catalyst and to provide a method for purifying an exhaust gas from a fuel direct injection type gasoline engine, by which the exhaust gas from the fuel direct injection type gasoline engine operated by changing the air/fuel ratio between the theoretical ratio and a ratio in a lean burn region is simply cleaned under any air/fuel ratio condition. SOLUTION : An exhaust gas such as the exhaust gas from the fuel direct injection type gasoline engine, which is changed correspondingly to the change of the air/fuel ratio between a 1st exhaust gas state based on the air/fuel ratio in the vicinity of the theoretical air/fuel ratio and a 2nd exhaust gas state based on the air/fuel ratio which is an oxidation atmosphere in comparison with the 1st exhaust gas state and has low temperature and has a larger air/fuel ratio than the theoretical air/fuel ratio, is cleaned by using the catalyst 12 for cleaning the exhaust gas prepared by supporting or mixing a noble metal such as platinum and an oxide of a rare earth on or with a fire resistant inorganic oxide having 50-200 m /g BET surface area to support and contain the noble metal by 0.01-50 g per 1 L catalyst volume.