| 摘要 |
PURPOSE: To efficiently remove nitrogen oxides in a gas flow by depositing a catalytically active material on a carrier comprising a porous alumina having a surface layer of at least one kind of a spinel compd. to prepare a catalyst. CONSTITUTION: An alumina carrier is impregnated with a soln. of at least one kind of a bivalent metal compd., dried at a temp. of 100 to 200 deg.C and calcined at a temp. of 700 to 1000 deg.C. Then, the carrier is impregnated with a soln. of at least one kind of a precursor of V, W, Mo, Fe and Co, dried at a temp. of 100 to 200 deg.C and calcined at a temp. of 400 to 600 deg.C to produce the catalyst for selective reduction of nitrogen oxides. The obtd. catalyst has a surface layer comprising at least one kind of a spinel compd. on a porous alumina carrier, and the catalyst carriers the catalytically active phase on the surface layer. As for the bivalent metal incorporated into the alumina carrier, Ni or Zn is preferable. |
