Nitrogen oxides reactions in diesel oxidation catalyst

摘要

Two catalyst formulations were tested on a diesel engine. A Fourier Transform Infrared (FTIR) analyzer was used to measure concentrations of nitric oxide (NO) and nitrogen dioxide (NO{sub}2). Other exhaust gas components were measured by conventional analyzers. The results indicate that nitrogen oxides (NO{sub}x) undergo complex chemical reactions in the diesel oxidation catalyst (DOC). The increase of NO{sub}2 occurring at a certain temperature range is accompanied by a decrease of the total NO{sub}x emission. NO{sub}2 is probably an important intermediate product in the lean NO{sub}x catalyst reaction chain.