| 摘要 |
The temperature stability of platinum-alumina catalysts is increased by adding to the alumina metal oxide stabilising components, specifically a) chromium oxide and/or tungsten oxide together with at least one oxide of a metal of the group IVB or b) an oxide of a material of the rare earths and at least one metal of the group IVB or c) an oxide of a metal of the rare earths and chromium oxide and/or tungsten oxide or d) an oxide of a metal of the rare earths, chromium oxide and/or tungsten oxide together with at least one oxide of the group IVB or e) an oxide of a metal of the rare earths, chromium oxide and/or tungsten oxide and additionally one or more oxides of calcium, strontium, barium, silicon and tin. For the purpose of the preparation, an intimate mixture of alumina or alumina-forming aluminium compound and the corresponding metal compounds which form metal oxides upon calcination, are calcined at a temperature of at least 850 DEG C, or 500 DEG C in the case of e), respectively, and a catalytic amount of platinum is intercalated. The stabilised alumina after calcining at 1200 DEG C for 2 hours has a surface of 20 m<2>/g. Said platinum-alumina catalysts are particularly suitable for the combustion of carbon-containing fuels. |
