| 摘要 |
PROBLEM TO BE SOLVED: To provide a catalyst for purifying exhaust gas which can improve NOx purification efficiency in a lean atmosphere SOLUTION: Rhodium, a fire resistant inorganic oxide, and tungsten are incorporated. The content of tungsten based on tungsten oxide is 150-500 g/liter. The content of rhodium, (1) in a mole ratio to the content of tungsten is 0.001-0.032, (2) 0.15-5.0 g per 1 liter of a catalyst, and the degree of dispersion of rhodium is 0.01-10%. The inorganic oxide is at least one selected from the group consisting of alumina, silica-alumina, titania-silica, magnesia-alumina, ceria-alumina, and zeolite. The mixture of the fire resistant inorganic oxide and tungsten oxide is impregnated with rhodium, dried by removing water, and burned at least 800 deg.C. |
