The kinetics of carbon monoxide and propylene oxidation as well as nitrous oxide reduction on a Pd-Rh catalyst were determined with synthetic gas mixtures between 500 and 700K. The overall reaction rate expression was constructed from elementary reaction steps and the kinetic parameters were determined from the experiments. A transient mathematical model has been developed to simulate automobile exhaust gas conversion based on the kinetics model equations. A comparison of simulated results with engine experiments proved to be successful. Results indicate that the reaction mechanisms proposed in this study are capable to describe the behavior of automotive exhaust gas converters, if mutual interactions of gaseous components and surface species are taken into account via elementary kinetic steps. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.