| 摘要 |
1282185 Purifying I C engine exhaust gases FORD MOTOR CO Ltd 4 Aug 1970 [22 Sept 1969] 37487/70 Heading F1B The exhaust gas stream from an I.C. engine operating with an air/fuel weight ratio not substantially lower than the stoichiometric is passed over a first catalyst for the oxidation of carbon monoxide and hydrocarbons, cooled to a temperature not substantially in excess of 900‹ F., e.g. 600 or 715‹F., and ammonia gas or a compound which readily releases ammonia, e.g. ammonium hydroxide, ammonium carbonate, urea, hexamethylene tetramine, hydrazine or ethylene diamine, or acts as its chemical equivalent is added to the cooled stream. The treated stream is then passed over a second catalyst promoting the reduction of nitrogen oxides. The first and second catalysts may be copper oxide or platinum or an alumina and an alumina-halogen support, respectively. Methods of producing the catalysts and numerical examples of their effect are given in the Specification. |
