DIFFUSION-REACTION OF CO, NO AND O₂ IN AUTOMOTIVE EXHAUST CATALYSTS.

Simulations of simultaneous diffuson and reaction of CO, NO and O//2 in the pores of three-waY catalysts are matched with experimental data to give estimates of intrinsic kinetics of CO-O//2 and CO-NO reactions. A steady state one-dimensional model for the monolith converter is developed, including heat and mass transfer between the bulk gas and the solid, and diffusion-reaction within the pores. Non-isothermality of the pores is accounted for by the internal-isothermal model, so that at any axial position within the converter they are isothermal, but at a temperature different from that of the bulk gas. Predictions of the model compare well with experiments.