The Effects of Alkaline Earth Metals on Catalytic Activities of K−Sm-Based Catalysts for Diesel Soot Oxidation

Abstract

The K-Sm catalysts added with alkaline earth metals supported on an R-porous alumina ceramic substrate have been prepared. XRD and TG-DSC were used to characterize the catalysts, and their catalytic activities were evaluated by a soot oxidation reaction using the TPR system. The TPR study showed that the catalyst with an 8.41 KNO 3 :Mg ratio had the lowest soot onset ignition temperature at about 318°C. It is very likely that the formation of liquid phases improves the catalyst/soot contact condition, which increases the catalytic activity of the catalyst. The catalyst containing a higher KNO 3 content exhibits CO 2 adsorption, whereas a definite-ratio alkaline earth metal can restrain the adsorption of CO 2 and the formation of Sm 2 O 2 CO 3 with a KNO 3 content less than a specified quantity.

Catalytic Combustion of Diesel Soot on Co−Sr−K Catalysts

“…Figure B shows the TPR curves of Co−Sr−K catalysts. It can be seen that there is a small peak below 200 °C, which should be the desorption of CO 2 adsorbed on the surface of catalysts …”

“…Catalytic Oxidation Activity Characterization. The temperature-programmed reaction (TPR) system was used to characterize the catalytic activities of the prepared catalysts. Before TPR testing, the supported catalysts were fumed above the burning diesel oil to be coated with a layer of soot.…”

Formation and Oxidation/Gasification of Carbonaceous Deposits: A Review

“…The activity order was found to be Y/K > La/K = Sm/K. Sui et al investigated the effect of alkaline-earth metals on the soot oxidation activity of porous alumina-supported K–Sm-based catalysts and concluded that the improved activity was likely due to the formation of a liquid phase of K–Sm–Mg …”

“…Sui et al investigated the effect of alkaline-earth metals on the soot oxidation activity of porous alumina-supported K−Sm-based catalysts and concluded that the improved activity was likely due to the formation of a liquid phase of K−Sm−Mg. 359 Table 11 summarizes the reaction rates and conditions for carbon oxidation reactions over multicomponent catalysts reported in the literature where enough information was provided to calculate rates. For most of the multicomponent catalysts in the table, their activities are not high, compared with ceria-based catalysts.…”

Photoelectrochemical Reduction of CO2in Methanol with TiO2Photoanode and Metal Cathode

“…Literature data for the solubility of CO 2 in pure methanol and water, at 15 o C, were of 4.6 and 1.07 cm 3 cm-3 , respectively. Therefore, methanol has been used as a physical absorbent of CO 2 [2].…”