Numerical Simulation on Oxidation Reaction of NO in Exhaust Gas by Pt Catalyst(Thermal Engineering)

Abstract

A high emphasis is placed on disposal of exhaust gas from diesel engines, because of an increasing concern about pollution of the atmosphere. Honeycomb supported catalytic agents is commonly used for NO oxidation into NO_2, which is adopted to develop continuously DPF system. However, the measurement of NO and NO_2 concentrations in the honeycomb is very difficult, because it is assembled with a lot of millimeter-sized channels. So, it is necessary to investigate and understand the phenomenon in the honeycomb by the numerical simulation. We have carried out the 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. Especially, the effects of the supported amount of catalyst, the composition and the temperature of inflowing exhaust gas on No oxidation have been examined, and the catalytic reaction mechanism has become clear.