Experimental and modeling study on zeolite catalysts for diesel engines

The work presented in this paper was aimed at detecting, understanding and modeling some critical behavior aspects of zeolite-containing diesel cataly sts. An already available mathematical model for precious metal catalysts w as used as a starting point. A specially designed set of experiments provid ed the information needed to improve certain modeling features. New submode ls were introduced to account for hydrocarbon and H2O adsorption, as well a s diffusion limitations in the zeolite. The effect of flow maldistribution during real world operation was investigated experimentally and computation ally. Although a number of issues (especially regarding the DeNOx mechanism s) are not yet fully resolved, significant progress was achieved as regards the understanding and computational prediction of diesel catalyst operatio n.