2011 Volume 6 Issue 2 Pages 437-451
A high emphasis is placed on exhaust gas disposal from diesel engines because of a growing concern about atmospheric pollution. Honeycomb-supported catalytic agents are commonly used for oxidation of NO into NO2, which is adopted to develop continuous regeneration-type DPF system. However, the measurement of NO and NO2 concentrations in the honeycomb is very difficult, because it is assembled with many millimeter-sized channels. Thus, it is necessary to investigate and understand the phenomenon in the honeycomb through a numerical simulation. We conducted a numerical study on NO oxidation by platinum catalyst in a channel using detailed elementary reaction kinetics for exhaust gas and platinum catalytic surface. Then, the details of NO oxidation on Pt surface in a channel, including species mass fraction in the gas, coverage on catalytic surface, and reaction rate of the elementary reaction, are obtained. In particular, the effects of the supported amount of catalyst as well as the composition and temperature of inflowing exhaust gas on NO oxidation have been examined; moreover, the catalytic reaction mechanism has been clarified.
