Durable Catalyst Formulations for Four-Stroke Small Engines

In this paper the development of durable Palladium containing catalytic coatings suitable for the application in a carbureted four-stroke multipurpose small engine is presented. The catalyst activity is evaluated with regard to the overall washcoat architecture in terms of i.e. implementation of oxygen storage material.

The basic parameters of all investigated fresh and thermally aged catalyst formulations are evaluated by light-off experiments using a synthetic gas test bench. In addition, engine test bench experiments are conducted to prove the catalyst activity in real application conditions. Finally a set of promising formulations are successfully submitted to a 125 hours durability test run with regard to the EPA III class I regulation [1].