Development of Paper Exhaust Catalyst Material for Emission Control in Small Internal Combustion Engines (2)

We investigated the catalytic performance of a porous-structured paper coated with precious metals such as palladium (Pd) and others. A honeycomb-shaped paper catalyst was successfully produced by paper making techniques, which are often used in the friction material manufacturing process for clutch system and the following newly developed molding process. As a new catalyst on the paper, Pd supported on Mn-substituted lanthanum hexa-aluminate (LaMnAl₁₁O₁₉, magnetoplumbite, MPB) crystallites with appropriate surface area was prepared and the catalytic performance, such as exhaust purification ability, was assessed using a model gas containing HC (hydrocarbon), CO (carbon monoxide) and NO (nitrogen oxide) gas. The results showed that Pd/MPB did not deteriorate even after 180 h aging at 1000°C. We concluded that the MPB has good potential as a catalyst component material for internal combustion engines because of the high thermal stability. As the coated paper canned in a stainless tube is so light-weighted that it would be suitable for a catalytic converter for small engines and general-purpose engines including agricultural and garden equipment, and particularly hand tools.