Development of catalysts for diesel particulate NOx reduction

While diesel vehicles feature high fuel economy with low CO2 emissions, further suppression of particulate matter (PM) and NOx in the exhaust stream is demanded worldwide. We have been working to develop a new diesel particulate-NOx reduction (DPNR) system to decrease both PM and NOx emissions by combining the NOx storage-reduction catalyst for direct injection gasoline engines with the most advanced engine control technologies. This paper describes the development of the DPNR system, a post-treatment technology for PM and NOx which was achieved through a combination of catalysis and engine control technologies.