Abstract: Method and apparatus for coating catalytic converter substrates with an exact amount of a precious metal. In the course of operation of the apparatus, a hollow substrate to be treated having opposed open ends is transferred from a starting location such that one end is lowered into a dip pan into which has been introduced a predetermined amount of slurry material containing the precious metal. With the one end immersed in the slurry, a vacuum placed on the other end of the substrate draws up the entire charge of slurry from the dip pan to coat the lower portion of the substrate. Thereafter, the substrate is raised from the dip pan. The vacuum continues to operate to cause the coating to be evenly distributed on all the interior surfaces of the substrate. Then the substrate is rotated and again lowered so that the other end is immersed in another predetermined charge of the slurry and the process is repeated. Thereupon, the substrate is again raised from the dip pan.

Abstract: A method for impregnating the interior skeletal structure of a ceramic monolithic catalyst support with a slurry of catalyst material is disclosed wherein a predetermined amount of catalyst slurry is metered into contact with a first end of the support. A cover is placed over the periphery of a second, opposite end of the support in sealing relation thereto to define a vacuum chamber adjacent the second end. A vacuum is drawn on the cover to draw catalyst slurry into the skeletal structure from the second end whereby the interior skeletal structure is uniformly impregnated with the catalyst slurry.

Abstract: Catalysts are disclosed which have good activity and life when used to promote the conversion of hydrocarbons, carbon monoxide and nitrogen oxides contained in small concentrations in gaseous streams, to obtain the less noxious materials, carbon dioxide, water and nitrogen. The catalysts contain a catalytically promoting, platinum group metal component, a catalytically promoting, base metal component and an alumina support component, deposited on a high surface area, particulate, macrosize carrier. The base metal component contains a metal selected from the group consisting of metals having an atomic number from 25 to 28 and rhenium.