초록 ▼

The present invention relates to a catalyst for purifying an exhaust gas, and in particular provides a catalyst for purifying an exhaust gas using a complex oxide, which is not deteriorated in its purifying performance even in a lean atmosphere containing sulfur dioxide SO.sub.2 at temperatures as h

The present invention relates to a catalyst for purifying an exhaust gas, and in particular provides a catalyst for purifying an exhaust gas using a complex oxide, which is not deteriorated in its purifying performance even in a lean atmosphere containing sulfur dioxide SO.sub.2 at temperatures as high as at least 1,000.degree. C., comprising at least one of the noble metals and one or at least two elements selected from the group consisting of alkaline earth metals and Group IIIA elements, and at least one member selected from the group consisting of iron, nickel and cobalt is supported in the surface portion of the catalyst, the catalyst further comprising, as a constituent element of the complex oxide, at least one element selected from the group consisting of iron, nickel and cobalt.

대표청구항 ▼

[ We claim:] [1.] A sulphur oxide resistant catalyst for purifying an exhaust gas, comprising:(i) a complex oxide containing at least one noble metal selected from the group of complex oxides having the formulas: X.sub.4 PmO.sub.6, wherein X is Ca, Sr, Ba or Mg; X'.sub.2 Pm.sub.2 O.sub.7, wherein X'

[ We claim:] [1.] A sulphur oxide resistant catalyst for purifying an exhaust gas, comprising:(i) a complex oxide containing at least one noble metal selected from the group of complex oxides having the formulas: X.sub.4 PmO.sub.6, wherein X is Ca, Sr, Ba or Mg; X'.sub.2 Pm.sub.2 O.sub.7, wherein X' is Sc, La or Pr; Sr.sub.3 X"PmO.sub.6, wherein X" is Co, Ni or Cu; Ba.sub.2 ZPmO.sub.6, wherein Z is Pr or Ce and Ba.sub.8 Y.sub.3 Pm.sub.4 O.sub.17.5), wherein Pm is Pt, Rh or Pd and from 1.0-10% by weight of at least one element selected from the group consisting of iron, cobalt and nickel, based on the total weight of noble metal containing complex oxide, supported on (ii) a catalyst support of the combination of (a) an alkaline earth metal element or a lanthanoid element and (b) an oxide selected from the group consisting of alumina, silica, titania, zirconia and ceria.