CATALYST FOR PURIFICATION OF EXHAUST GAS AND METHOD FOR PURIFYING EXHAUST GAS

摘要

PROBLEM TO BE SOLVED: To obtain a catalyst capable of efficiently removing NOx in exhaust gas from an internal combustion engine operated in a lean burning region and to provide a high reliability method for purifying exhaust gas with the catalyst by which NOx in exhaust gas from an internal-combustion engine can be removed with high efficiency. SOLUTION: Silver, zinc and acidic anions are incorporated into alumina to obtain the objective catalyst having the below-mentioned relation between pore diameter and pore volume measured by a gaseous nitrogen adsorption method. The total pore volume of pores each having 25 to <100Å pore diameter is >=70% of that of pores each having <=300Å pore diameter and the total pore volume of pores each having 100-300Å pore diameter is <=20% of that of pores each having <=300Å pore diameter. This catalyst is incorporated into a denitration catalyst layer and exhaust gas is purified.