| 摘要 |
PURPOSE:To obtain a cheap catalyst for decomposition of nitrogen oxides which can easily be manufactured by using a multiple oxide of lanthanum and zirconium with smaller proportion of zirconium than the specified value to lanthanum. CONSTITUTION:A multiple oxide of lanthanum and zirconium with <1.0 molar ratio of zirconium to lanthanum, preferably, 0.05-0.2 molar ratio, is used. Or, a multiple oxide of lanthanum, zirconium and magnesium obtd. by adding magnesium by <5 molar ratio to the zirconium of the above catalyst is used. Then, zirconium intrudes into the lattice of lanthanum oxide and substites to generate strain in the crystalline structure of lanthanum oxide, or zirconium oxide partly changes into amorphous, and thereby lots of surface active points are produced. Addition of magnesium improves dispersibility of the catalyst. Therefore, the catalyst can easily be preared at low cost. |
