摘要 |
Nitrogen oxides, NOx, are depleted/removed from oxygen-containing gas streams comprising same, by contacting an admixture of ammonia and such gas streams, at elevated temperatures, with a catalyst which comprises a catalytically active metallic oxide deposited on a porous alumina support, said support comprising a volume of pores having diameters larger than 1000 A in excess of 25 cm3/100 g, a volume of pores having diameters larger than 300 A in excess of 40 cm3/100 g, a total pore volume of from about 80 cm3/100 g to 120 cm3/100 g, and a surface area of less than 160 m2/g, said catalytically active metallic oxide being an oxide of a metal selected from the group consisting of vanadium, iron and cobalt, and said catalytically active metal oxide comprising from 0.5 to 20% by weight of the catalyst. |