Catalytic converters are used to control the emission of automobiles under highly transient conditions. In this study, one-dimensional unsteady state model for an automotive catalytic converter is described and solved. Its transient behavior has been studied using a mathemetical model, based on the concurrent process of chemical reaction, heat transfer, and mass transfer. The responses of catalytic converter have been studied about external disturbances, such as, step change and periodic square pulse of gas temperature and gas concentration, change of converter design parameters, operating conditions, etc. It is also studied the relationship between occurrence of thermal boundary layer and inlet temperature of gas. A real-time displaying simulator for automotive catalytic converter has been developed consquently, which enables to change input parameters and conditions by user.
