METHOD FOR REDUCING NOX

摘要

PURPOSE:To efficiently reduce NOx at a low temp. by allowing a small amt. of hydrogen to coexist with NOx-contg. exhaust gas. CONSTITUTION:A catalyst is composed of a porous carrier having a zeolite type structure in which the molar ratio of SiO2 to Al2O3 is 10-200 and platinum carried on the porous carrier by >=0.1wt.%, and NOx-contg. exhaust gas is brought into contact with the catalyst under coexistence of gaseous hydrogen to reduce the NOx. Since the porous carrier has high hydrophobic property, the sticking a of steam to the surface of the catalyst is prevented and a reduction reaction of NOx proceeds smoothly.