A detailed surface reaction mechanism for CO oxidation on polycrystalline Pt surfaces, capable of predicting different experimental features, was developed using a multi-step methodology. Thermodynamically consistent, coverage-dependent activation energies and heats of reactions were obtained from the application of the Unity Bond Index-Quadratic Exponential Potential formulation. Initial estimates of pre-exponentials were determined from transition state theory or available studies. Model validation with independent experiments revealed that the proposed surface reaction mechanism performed very well. The potential of the approach for developing surface reaction mechanism for catalytic combustion of more complex fuels was elucidated. Original is an abstract.