Design Criteria of Catalyst Substrates for NOx Adsorber Function

Against the background of the current discussions on the reduction in CO₂ emissions, the development of lean-burn engines is acquiring increasing importance. In order to meet future emissions limits, new strategies are required, especially for NO_x conversion. One technique developed in recent years for the conversion of NO_x in lean exhaust gases is the NO_x adsorber catalyst, which stores NO_x in lean operating conditions and must periodically be regenerated with rich exhaust gas.

In this paper, the influence of catalyst substrate design on NO_x conversion is described. In addition NO_x conversion measurements with NO_x adsorbers of various cell densities, variable diameter/length ratios as well as smooth and structured channel walls are carried out.