Catalyst for reducing nitrogen oxides in exhaust gas from gasoline and diesel engines

摘要

The catalyst for reducing nitrogen oxides in an oxidizing and reducing atmosphere contains iridium on a support material made of silicon dioxide or zeolite. The iridium on the outer surface has an average particle size of 5-30 nm. An Independent claim is also included for the production of the catalyst comprising impregnating the support material with a soluble precursor of iridium, drying the impregnated material and calcining in a gas stream containing hydrogen at 300-500 deg C for 1-10 hours.