Reduction catalysts and processes for reduction of nitrogen oxides

摘要

The reduction of nitrogen oxides involves the passage of gases containing nitrogen oxides at higher than 500 DEG C. over a catalyst comprising cerium oxide and nickel oxide in the CeO2/NiO molar ratio of about 0.05 : 1 to 2.5 : 1 and when desired an addition thereto of rhodium in an amount of from about 7.5 to 25 parts by weight per 100 parts by weight of the nickel oxide and cerium oxide composition and when desired an addition to said nickel oxide and cerium oxide composition of ruthenium in an amount of about 10 to 50 parts by weight or an addition to said composition containing rhodium of ruthenium in an amount of about 15 to 50 parts by weight per 100 parts by weight of the nickel oxide and cerium oxide composition. Also, when desired, an addition to said composition of one or more metal sulfides and an addition to said composition of one or more metal oxides is utilized.