Catalyst for Use in a Process for Purifying Exhaust Gas from Gasoline Engines of a Fuel-direct-injection Type

A catalyst for use in a process for purifying exhaust gas from gasoline engines of a fuel-direct-injection type, wherein the process includes, as exhaust gas conditions, (i) a first exhaust gas state in which an air-fuel ratio is in a range of 13 to 15, and an exhaust-gas temperature is in a range of 350 to 800° C. at an inlet of the catalyst and (ii) a second exhaust gas state in which the air-fuel ratio exceeds an air-fuel ratio of 15, and the exhaust-gas temperature is in a range of 200 to 500° C. at the inlet of the catalyst,

• the catalyst being obtained by causing a noble metal and a rare-earth oxide and/or a transition metal to be carried by or to be mixed with a fire-resistant inorganic oxide,
• the fire-resistant inorganic oxide having a BET surface area in a range of 50 to 200 m2/g and a pore diameter in a range of 10 to 30 nm,
• the catalyst containing the noble metal in a range of 0.01 to 50 g/liter with respect to a catalyst volume,
• the fire-resistant inorganic oxide being at least one kind of α-alumina, γ-alumina, δ-alumina, η-alumina, active alumina of θ-alumina, titania, zirconia, and composite oxides thereof.