CATALYST FOR CONVERSION OF NOXIOUS COMPONENTS OF EXHAUST GASES OF INTERNAL COMBUSTION ENGINES AND PROCESS FOR PREPARING THEREOF

摘要

This particle catalyst for transforming harmful components of combustion engine exhaust gas into relatively harmless burnt products contains metals of the group of noble earths, in particular cerium, lanthanum, praseodymium and neodymium, and as the active components 0.001 to 5% by weight of platinum or/and palladium or metals of the 1. b group or the periodic system of elements, in particular copper, in a weight ratio to the precious metals of group VIII of 1 : 0.1 to 2, on the active wide-pore aluminium oxide of boehmitic group with at most 0.01 % by weight of Na. The method of preparing this catalyst is based on the precipitation of the wide-pore aluminium hydroxide, drying, mixing with the compounds of the noble earths, processing this material into particles that are thermally activated at temperatures of 100 to 1,000 degrees C, on these thermally processed particles precious metals of group VIII of the periodic system are introduced either independently or in mixture and possibly also a salt of the metal of the 1. b group and these modified particles are again thermally activated at a temperature of 100 to 600 degrees C.