Mazda Motor Corporation will receive the “Outstanding Technical Paper Award 2008” at the 58th Annual Society of Automotive Engineers of Japan (SAEJ) awards ceremony to be held in May. The company is being recognized for a method for the in-depth analysis of the combustion mechanism of catalysts in diesel particulate filters.
Mazda has been conducting research into more efficient combustion mechanisms to eliminate particulate matter from diesel engine exhaust emissions. Active regeneration of diesel particulate filters can use a variety of mechanisms to enable combustion to remove the particulate matter (soot) that accumulates in the filter. All the mechanisms, however, require extra fuel—although the amount will vary based on the strategy—which is one of the causes of impaired fuel economy.
Mazda developed an original analytical method which demonstrated that the oxygen exchange characteristics of catalysts play an important role in accelerating the combustion of particulate matter.
Specifically, the Mazda researchers investigated oxygen storage components (OSC) based on cerium (Ce) for their ability to reduce the oxidation temperature of diesel particulate matter (DPM). A cerium-praseodymium (Ce-Pr) composite oxide provided the largest reduction in DPM oxidation temperature. Oxygen isotope tracer experiments revealed that oxygen released from the cerium oxidized the DPM at a lower temperature than the oxygen from the exhaust.
Mazda will leverage its new analytical method to find ways of accelerating particulate matter combustion in order to significantly reduce exhaust processing times. By developing this technology, Mazda intends to cut the fuel consumption of future models and achieve cleaner exhaust emissions, together with reduced CO2 output.
In 2007, Mazda filed a patent on a new catalytic material for removing diesel particulates. The material is a composite oxide which contains zirconium as a primary component and a rare-earth metal except for cerium and yttrium. The composite oxide has a crystallite diameter of 13 nm to 40 nm.
Additionally, the newly-developed analytical method can be applied not only to automobile diesel engines, but also to general-purpose diesel engines. The award recognizes these achievements, which provide tangible development guidelines for a wide range of future diesel engine technologies.
The 2008 SAEJ award will be Mazda’s fourth SAEJ award since 2005.
Kenji Suzuki, Koichiro Harada, Hiroshi Yamada, Kenji Okamoto and Akihide Takami (2007) Study on Low-Temperature Oxidation of Diesel Particulate Matters by Oxygen Storage Component for the Catalyzed Diesel Particulate Filter (SAE 2007-01-1919)
US Patent Application US 2007/0191219 A1. Catalytic Material, Production Method Therefor, and Diesel Particulate Filter