Modelling three-way catalytic converters: an effort to predict the effect of precious metal loading

The need to deliver ultra-low emitting vehicles at a reasonable cost is driving the automotive industry to invest significant manpower in computer aided design and optimization of exhaust treatment systems. The significant fluctuations in the stock exchange market values of the precious metals employed in the manufacture of automotive catalytic converters has increased interest in the possibility of assisting precious metal loading optimization by means of mathematical modelling. Currently employed models of real world performance of catalytic converters cannot predict this effect. Recent improvements in the core chemical reaction modelling of the CATRAN code, reported in this paper, allow a good correlation to be made of precious metal loading with apparent kinetics, at least in the case of Pt-Rh catalysts. This may open new frontiers to the use of mathematical modelling in automotive exhaust after-treatment system optimization.