PURIFICATION OF EXHAUST GAS

摘要

PURPOSE: To further efficiently purify NOx in oxygen excessive exhaust gas. CONSTITUTION: A catalyst prepared by supporting a catalytic noble metal on Y-type zeolite or mordenite is arranged in a passage of oxygen excessive exhaust gas and exhaust gas is brought into contact with the catalyst while paraffinic HC is added to the exhaust gas to reduce and purify NOx contained in the exhaust gas. Since the pore size of Y-type zeolite or mordenite is relatively large as compared with that of other zeolite, Y-type zeolite or mordenite is considered to be excellent in the adsorbability of paraffinic HC having a high mol.wt. and shows high NOx purifying capacity.