| 摘要 |
1465986 Exhaust gas purification catalysts HOECHST AG 12 Nov 1974 [24 Nov 1973] 48885/74 Heading BIE [Also in Division Cl] Catalysts comprise a ceramic honeycomb structure coated with a layer of alumina carrying copper, nickel and manganese oxides applied by impregnation after the coating of the carrier. They may be made by heating the honeycomb to 300-400‹C, introducing it while hot into a concentrated solution of an aluminium salt of a volatile acid for 15-60 min, blowing out excess solution, drying the carrier at room temperature, heating the dry carrier for 1-4 hr. at 350-450‹C, calcining at 500-700‹C for 2-6 hr., heating to 300-400‹C, dipping while hot into a hot concentrated solution of copper, nickel and manganese salts of volatile acids for 15-60 min, blowing out the excess solution, drying for 1-4 hr at 350-450‹C and calcining at 700-1000‹C for 5-20 hrs. The catalyst may be reduced by heating in an atmosphere containing a minor proportion of a gaseous reducing agent. |
