EXHAUST GAS TREATMENT CATALYST, METHOD FOR PRODUCING EXHAUST GAS TREATMENT CATALYST, AND EXHAUST GAS TREATMENT SYSTEM

Provided is a method for producing a denitration catalyst for denitrating an exhaust gas from a sintering furnace using CO as a reducing agent. The denitration catalyst comprises a carrier that is titanium dioxide or silicon dioxide, and an active metal including at least iridium supported by the carrier, wherein a BET specific surface area of the denitration catalyst is 100 m/g or less, and wherein a crystallite diameter of iridium in the denitration catalyst is 12 nm or more and 23 nm or less. The method comprises an impregnation and supporting step of impregnating the carrier with iridium to be supported thereby; a first firing step of firing the carrier supporting iridium; and an activation step of activating the carrier by heating the carrier in a reducing gas atmosphere after the firing, wherein a BET specific surface area of the carrier in the impregnation and supporting step is 100 m2/g or less, as calculated using a BET method, and wherein, in the activation step, a heating temperature is set to 400°C or higher and 1,000°C or lower, a heating time is set to 0.5 hours or longer and 50 hours or shorter, and hydrogen, carbon monoxide, or a gas mixture thereof is used as the reducing gas.