METHOD FOR REMOVING NITROGEN OXIDE

摘要

PURPOSE: To effectively remove NOx by using a catalyst prepared by mixing a multiple oxide consisting of Mn and the metallic elements other than Mn in the zeolite contg. >=1 kind of transition metal and with the SiO2 /Al2 O3 molar ratio specified. CONSTITUTION: A catalyst prepared by mixing a multiple oxide consisting of Mn and the metallic elements other than Mn in the zeolite contg. >=1 kind of transition metal and with the SiO2 /Al2 O3 molar ratio controlled to >=15 is brought into contact with an oxygen-excess waste gas contg. NOx and hydrocarbons. The zeolite has to contain >=1 kind of transition metal. The transition metal is added preferably in 0.2-20 atomic ratio to the Al in the zeolite. The zeolite contg. transition metals must be mixed with the multiple oxide contg. Mn and the metallic elements other than Mn. The multiple oxide is the compd. of >=2 kinds of metals and oxygen or the mixture of >=2 kinds of metal oxides.