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.
IN A METHOD FOR ELIMINATING TOXIC SUBSTANCES CONTAINED IN EXHAUST GASES CONTAINING NITROGEN OXIDES, THE IMPROVEMENT WHICH COMPRISES CONTACTING AN EXHAUST GAS WITH A CATALYTIC COMPOSITION DEPOSITED ON A CARRIER AND COMPRISING: A. IRON, IRON OXIDE OR IRON SULFIDE; B. SILVER, SILVER OXIDE OR SILVER SULFIDE; AND C. AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF COPPER, BERYLLIUM, ZINC, LEAD, INDIUM, LANTHANUM, CERIUM, AND OXIDES THEREOF AND COPPER SULFIDE.
Claim 2
Dependent Claim
71 words
IN A METHOD FOR ELIMINATING TOXIC SUBSTANCES CONTAINED IN EXHAUST GASES CONTAINING NITROGEN OXIDES, THE IMPROVEMENT WHICH COMPRISES CONTACTING AN EXHAUST GAS WITH A CATALYTIC COMPOSITION DEPOSITED ON A CARRIER AND COMPRISING: A. IRON, IRON OXIDE OR IRON SULFIDE; B. SILVER, SILVER OXIDE OR SILVER SULFIDE; AND C. AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF COPPER, BERYLLIUM, ZINC, LEAD, INDIUM, LANTHANUM, CERIUM, AND OXIDES THEREOF AND COPPER SULFIDE.
Claim 3
Dependent Claim
20 words
A method according to claim 1 wherein the exhaust gas is an exhaust gas discharged from an internal combustion engine.
Claim 4
Dependent Claim
14 words
Method according to claim 1 wherein said catalyst is deposited on an alumina carrier.
Claim 5
Dependent Claim
25 words
Method according to claim 1 wherein said catalyst is in admixture with powdered alumina, finally divided cellulose and alumina sol and is in spherical form.