Catalytic Combustion of Diesel Soot over Ce_{0.5+<em>x</em>}Zr_{0.4-<em>x</em>}La_0.1O₂-Al₂O₃ Catalysts

Abstract

Ce0.5 + x Zr0.4-x La0.1O2-Al2O3 catalysts were prepared by co-precipitation, where 0≤x≤0.4 and the mass ratio of Ce0.5 + xZr0.4-xLa0.1O2:Al2O3 was 1:1. The catalytic activities of these catalysts for the catalytic combustion of diesel soot were investigated. The catalysts were further characterized by low temperature nitrogen adsorption-desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2temperature-programmed reduction (H2-TPR), and O2-temperature-programmed desorption (O2-TPD). The results showed that all the catalysts formed solid solutions with a fluorite-like structure. When x=0.2, the Ce 3 + ions were partly rich on the surface of the catalyst. The catalyst was easily reduced by H2 and the desorption peak area of the β oxygen species was the largest. The light-off temperature was 360°C for the catalytic combustion of diesel soot over the catalyst suggesting good catalytic activity and potential application in diesel soot catalytic combustion.

Influence of La on CeO₂-ZrO₂ Catalyst for Oxidation of Soluble Organic Fraction from Diesel Exhaust

“…So α O species may participate in the reaction and the activity of the catalysts may be related to the amount of the chemical adsorbed oxygen. 28 And the orders of the ratio of α O species are in accordance with the orders of T l and T m (in Table 1). More amount of α O species is, the lower T l and T m are, thereby, La-modified CeO 2 -ZrO 2 catalysts show better activities than CeO 2 -ZrO 2 catalysts.…”

“…[25][26][27] Theoretically, both adsorbed and lattice oxygen can take part in the oxidation. 28 But for the oxidation of SOF, what kinds of oxygen species are good for the reaction? In order to answer the question, O 2 -TPD is employed.…”