Kinetic modelling of aftertreatment systems have become a major part of catalyst evaluation and development. A large number of kinetic models have appeared in literature over the past number of decades, varying in application from single reaction models to models capable of simulating a full reaction set for automotive application. All the kinetic models however use either one of two approaches, global kinetics or microkinetics. The kinetic model developed in this work uses both kinetic approaches, allowing the user to select the kinetic approach required for the simulation for each individual reaction. The work presented in this report details the theory behind the kinetic model and development of the micro kinetic and dual kinetic routines. The model is validated against a range of experimental data consisting of end pipe, spatially resolved and vehicle data. Simulations conducted using the -kinetic model proves accurate for each of the kinetic approaches used (global kinetics, micro-kinetics and dual kinetics). with a comparison of each kinetic approach conducted throughout. Integrating micro-kinetics into the kinetic model increased the accuracy of the simulations for the conditions conducted, providing more information for the CO oxidation than previously available using the global kinetic approach. The dual kinetic approach incorporating global kinetics and micro-kinetics provided more accurate results than a purely global kinetic model. The model has been developed to support the further development and expansion of the micro-kinetic reactions.