In this work a simple 1-D model for the macro kinetic conversion behaviour of a commercial automotive Three-way-exhaust catalyst for a Turbocharged DI-Gasoline-Engine is realized using GT-Power. A detailed reaction kinetic model to predict the activity of the commercial three way catalyst has been adopted from Young-Deuk [1], considering all possible reactions in the catalytic converter based upon the Langmuir-Hinshelwood mechanism. 1D model was later modified for the laboratory scale catalyst and validated against synthetic gas test bench data.