| abstract |
Toxic substances contained in exhaust gases, especially nitrogen oxides contained in exhaust gases from automobiles, can be effectively eliminated, even in the presence of oxygen, by contacting such exhaust gases with a catalyst composition comprising iron or iron oxide, silver or silver oxide, at least a member selected from the group consisting of copper, beryllium, zinc, lead, indium, lanthanum, cerium and oxides of these metals, and a carrier. Especially good results can be obtained by employing a catalyst composition obtained by treating a composition comprising iron or iron oxide, silver or silver oxide, copper or copper oxide and a carrier with hydrogen sulfide, or by employing a catalyst composition comprising sulfides of iron, silver and copper supported on a carrier. |