THREE-WAY CATALYST, AND METHOD FOR CLEANING EXHAUST GAS BY USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a three-way catalyst which exhibits such excellent exhaust gas cleaning performance (highly excellent catalytic activity) that HC, CO and NOx contained in the exhaust gas can be cleaned efficiently even when a noble metal is not used therein, and to provide a method for cleaning exhaust gas by using the three-way catalyst.SOLUTION: The three-way catalyst is brought into contact with the combustion exhaust gas containing hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NOx) to remove the three components and contains: a carrier containing cerium oxide (CeO); and copper (Cu) and tungsten (W) carried by the carrier. A ratio of the amount of Cu to be carried (in terms of CuO) and the amount of W to be carried (in terms of WO) to the specific surface area of the carrier satisfies a relationship shown by the following inequality (1).