A modeling and simulation study on Pt-catalyzed conversion of automotive exhaust gases is presented. The model is based on a newly developed surface reaction mechanism consisting of 73 elementary-step like reactions among 22 surface and 11 gas-phase species. Reactions for the conversion of the major pollutants CO, CH4, C3H6, and NOx are included. The mechanism is implemented in a two-dimensional flow field description of a single channel of the catalytic monolith. The model is evaluated by comparison with data derived from isothermal laboratory experiments in a flat bed reactor with platinum-coated monoliths using synthetic lean/rich cycling exhaust gas mixtures. The influence of CO and C3H6 at lean and H-2 at rich conditions on NO conversion is investigated, both at steady-state conditions. Furthermore, the model is also applied for the simulation of emissions of hydrocarbons, CO, and NO from a gasoline engine (stoichiometric exhaust gas) in a dynamic engine test bench. (C) 2009 Elsevier B.V. All rights reserved.