Honeycomb catalysts for clean-up of diesel exhausts based upon the anodic-spark oxidized aluminum foil

The technology of the aluminum foil anodic spark oxidation in the water-bas ed electrolytes has been applied to form strongly adhering protective alumi na layer at the surface. Basic features of the oxidation were studied by SE M and XRD. Secondary supports, promoters and modifiers including rare-earth elements were used to increase the thermal stability of these composites u p to 900 degrees C. These materials were assembled as thin wall honeycomb s upports loaded with a number of active components, The catalysts were teste d in the reactions of CO and CHx oxidation, NOx selective reduction by hydr ocarbons and demonstrated a high performance and a low pressure drop at hig h space velocities. City diesel buses field tests of converters equipped wi th those catalysts demonstrated their high and stable performance in clean- up of exhausts from SOE CO, gaseous hydrocarbons and NOx. (C) 1999 Elsevier Science B.V. All rights reserved.