Coated film of catalytically active oxide on a refractory support

Abstract

Abstract A CATALYST COMPOSITION IS MADE HAVING A PLATINUM GROUP METAL AND A FILM OF CATALYTICALLY ACTIVE METAL OXIDE SUPPORTED ON AN INERT, SUBSTANTIALLY CATALYTICALLY INACTIVE REFRACTORY SUPPORT WHICH EXHIBITS A POROSITY OF AT LEAST 0.03 CC./GM., SAY 0.1 TO 0.3 CC./GM., AND A SUBSTANTIAL WATER PORE VOLUME. THERE ARE UNOBSTRUCTED OPENINGS OR CHANNELS GOING THROUGH THE SUPPORT THROUGH WHICH PASS THE CHEMICAL MATERIALS CONVERTED BY THE CATALYST, E.G. AUTOMOBILE EXHAUST GASES AND OXYGEN, DURING ITS USE. CALCINED ALUMINA IS A SUITABLE FILM OR CATALYTICALLY ACTIVE METAL OXIDE AND ALPHA-ALUMINA AND ZIRCON-MULLITE CAN BE USED AS SUPPORTS. THE SUPPORT IS MAINLY CRYSTALLINE AND CAN HAVE A MACROPORE DISTRIBUTION SUCH THAT OVE 95% OF THE PORE VOLUME IN IS PORES HAVING A DIAMETER OF OVER 2,000 A. AND OVER 5% OF THE PORE VOLUME IS IN PORES HAVING A DIAMETER OF OVER 20,000 A. ONE WAY OF MAKING THE CATALYST IS TO DEPOSIT THE FILM ON THE SUPPORT AND THEN IMPREGNATE THE FILM WITH THE PLATINUM GROUP METAL. THE PLATINUM GROUP METAL CAN BE FIXED ON THE SUPPORT BY TREATMENT WITH, FOR INSTANCE, HYDROGEN SULFIDE. AS A FINAL PREPARATION STEP THE CATALYST CAN BE CALCINED.

Inventors

• 👤 Carl D Keith
• 👤 Paula M Kenah
• 👤 Daniel L Bair

Bibliographic Details