| 摘要 |
An exhaust gas catalytic surface has a powdered substrate bearing a noble metal (gold, silver, platinum, palladium, rhodium, ruthenium, iridium or osmium) or an alloy containing one or more of these metals. The noble metal crystals deposited upon the substrate have especially a relative radiological crystallinity of more than 2 and a median particle size between 2 and 10 nm. Preferred Features: The relative radiological crystallinity is greater than 5. The substrate material contains carbon and is based on soot, graphite, active carbon, and fibre-formed graphite nano-tubes. The substrate material is an oxidized material based on aluminum oxide, aluminum silicate, zeolite, titanium oxide, zircon oxide, rare dioxides, or mixtures of these. The noble metals also incorporate alloys from the group titanium, zirconium, carbon, chromium, manganese, iron, cobalt, nickel, copper or zinc. The catalyst has platinum on soot of at least 40 m/g in a concentration of 5-80 wt.%, w.r.t the total weight of the substrate material and platinum. An Independent claim is also included for the production of a fuel cell catalyst. |
