Effect of Potassium on Sol-Gel Cerium and Lanthanum Oxide Catalysis for Soot Combustion

Abstract

The catalytic activity in the soot combustion is reported for a series of potassium-promoter alumina supported catalysts prepared by the sol-gel method to be used in the catalytic combustion of soot. The studied systems correspond to CeO 2-Al 2 O 3 and La 2 O 3-Al 2 O 3 with charges of 3 and 5 wt% of CeO 2 and La 2 O 3. Potassium impregnation is performed to reach 3 atoms of K per nm 2 of the mixed oxide. The effect of the potassium incorporation increases its reducibility, decreases the surface area and forms a new type of oxygen that is stronger than the oxygen in mixed oxides with similar chemical nature. The existence of potassium oxides, K 2 O and oxygen responsible for the vacancies and/or lattice defects (O 2−) are related to good catalytic activity. Additionally, the presence of alkali affects the structural and textural characteristics of the catalyst, promoting the catalytic activity in soot combustion.

Nano-magnetic potassium impregnated ceria as catalyst for the biodiesel production

“…New peaks at around 833 cm -1 and 1390 cm -1 indicates impregnation of potassium to the catalyst. nanocatalyst [15,25]. Table 1 shows the crystallographic parameters of Fe3O4-CeO2-25K…”

Structural and mechanical properties of lanthanide doped La1/3Nb0.8Ta0.2O3 thin films prepared by sol–gel method

“…XPS measurements were performed to determine the chemical states of each element on the surface of three different tartrate gels. Figure 1 shows the XPS survey spectra of the [33]. The position of the Nb3p multiplet(douplet) of LNT(LNT:Nd) and BE from 375.9(378.6) eV (Nb3p 1/2 ) to 364.9(363.1) eV between the La3d 5/2 and La3d 3/2 peaks indicate the Nb 5+ oxidation state [34].…”