Alkaline-earth metal doped K-V catalysts for diesel soot combustion-preparation, characterization and catalytic properties

The K- V- alkaline- earth metal catalysts supported on alpha- alumina ceramic substrate have been prepared. The morphology of the soot particulates deposited on prepared catalysts supported on a- alumina ceramic substrate was described by scanning electron microscopy ( SEM). The XRD was used to characterize the catalysts and their catalytic activities were evaluated by soot oxidation reaction using the TPR system. The SEM photographs presented that soot particles have a particle size of about 100 nm in diameter forming a loose contact with catalyst, which is resemble to the real situation for the catalyst application. The XRD and TPR study showed that the catalytic activities of the catalysts were improved through the cooperation of KNO3 and some alkaline earth metal compounds. The soot onset ignition temperature at 310 degrees C is the lowest by the cooperation of the crystalline phases KNO3, KCaVO4, and Ca-3( VO4)(2) for the K- V- Ca catalyst with a molar ratio of 6: 1: 1. In addition, the catalyst containing higher KNO3 content has an adsorption for CO2. The all prepared K- V- Ba catalysts can adsorb more CO2 at room temperature.