Effect of Support on a Catalytic Converter for Removing CO and HC Emissions from a Two-Stroke Motorcycle

Abstract

The effect of support on the noble metal catalysts for carbon monoxide and hydrocarbon oxidation was investigated. The reactions were performed under the stoichiometric and oxygen-deficient conditions. Under the stoichiometric point, the activities of the powder catalysts for CO and C3H6 oxidation are in the order Pt/K2O/Al2O3 > Pt/Al2O3 > Pt/Al2O3−SiO2, that is, the same as the order of basicity of these catalysts. Under an oxygen-deficient condition, Pt supported on an acidic support, Al2O3−SiO2, exhibits the higher C3H6 conversion and the higher activity for the steam re-forming reaction. In contrast, Pt supported on a basic support, K2O/Al2O3, exhibits the higher CO conversion and the higher activity for the water−gas shift reaction. The order of activity of the powder catalysts for the water−gas shift reaction is the same as the order of basicity of these catalysts. On the other hand, the testing results of the monolithic PtRh-containing catalysts by the simulative gases and the ECE-40 mode driving cycle also reveal the same trend as that of the Pt powder catalysts. Furthermore, the addition of K2O on PtRh/Al2O3−CeO2 not only increases the basicity of the catalyst but also significantly reduces the CO emission under the ECE-40 mode driving cycle test. Therefore, K2O could be a promising additive to a catalytic converter of a two-stroke motorcycle since it can significantly enhance CO conversion.

Activated Carbon and Tungsten Oxide Supported on Activated Carbon Catalysts for Toluene Catalytic Combustion

“…The catalytic process permits energy saving and minimizes other negative effects such as NO x formation, although the formation of intermediate oxidation products, such as dioxins, should be controlled. Catalysts based on noble metals (Pt, Pd, Rh) supported on different materials present high activity and selectivity to the complete pollutant oxidation ( − ). However they are expensive, susceptible to poisoning ( 2 , − and show, in some cases, a poor thermal stability.…”

“…Moreover, organic compounds are more readily adsorbed on hydrophobic surfaces (3). Acidity is also expected to be a favorable factor for combustion catalysts since it is known that the acid character of supports or catalysts favors the oxidation reactions of organic compounds (1,11,12).…”