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The California Air Resources Board (CARB) has recently adopted direct ozone reduction (DOR) technologies as an emission control alternative. The application of DOR technologies on motor vehicles allows an automaker to receive non-methane organic gas (NMOG) emission credits, which may be applied to offset vehicle tailpipe emissions or evaporative emissions from fuel tanks. Additionally, DOR technologies can enhance the “green image” of an automaker. DOR devices involve catalyst coatings on radiators or other surfaces in such a way that the amount of ozone in the ambient air passing through such surfaces is reduced. The deposition of catalysts onto substrates (e.g. radiator surfaces) is traditionally accomplished using a slurry process, which often involves multiple steps in coating formation. In this work, deposition of catalytic coatings onto radiator surfaces via kinetic and thermal spray processes is explored.

The major challenge in diesel NOx aftertreatment systems using NOx adsorbers is their susceptibility to sulfur poisoning. A new computational model has been developed for the thermal management of NOx adsorber desulfation and describes the exothermic reaction mechanisms on the catalyst surface in the diesel NOx trap. Sulfur, which is present in diesel fuel, adsorbs as sulfates and accumulates at the same adsorption sites as NOx, therefore inhibiting the ability of the catalyst to adsorb NOx. Typically, a high surface temperature above 650 °C is required to release sulfur rapidly from the catalyst [1]. Since the peak temperatures of light-duty diesel engine exhaust are usually below 400 °C, additional heat is required to remove the sulfur. This report describes a new mathematical model that employs Navier-Stokes equations coupled with species transportation equations and exothermic chemical reactions.