Effect of oxygen vacancy and highly dispersed MnOx on soot combustion in cerium manganese catalyst

Cerium manganese bimetallic catalysts have become the focus of current research because of their excellent catalytic performance for soot combustion. Two series of cerium manganese catalysts (Na-free catalysts and Na-containing catalysts) were prepared by coprecipitation method and characterized using XRD, N₂ adsorption-desorption, SEM, Raman, XPS, H₂-TPR, O₂-TPD, Soot-TPR-MS and in situ IR. The effects of abundant oxygen vacancies and surface highly dispersed MnO_x on soot catalytic combustion of cerium manganese catalysts prepared by different precipitants were analyzed. The activity test results show that the active oxygen species released by a large number of oxygen vacancies in the cerium manganese catalyst are more favorable to the soot catalytic combustion than MnO_x which is highly dispersed on the surface of the catalyst and has good redox performance at low temperature. Because the catalytic effect of MnO_x on the surface of Na-free catalysts is more dependent on the contact condition between the catalyst and the soot, this phenomenon can be observed more easily under the loose contact condition than under the tight contact condition. The activity cycle test results show that these two series of catalysts show good stability and repeated use will hardly cause any deactivation of the catalysts.

Superior catalytic performance of a CoOx/Sn–CeO2 hybrid material for catalytic diesel soot oxidation

A Co₃O₄/Sn–CeO₂ hybrid catalyst exhibited superior soot oxidation activity due to the existence of synergism among the multivalent cations and the stepped surface of the hybrid catalyst.

Investigation on the physicochemical properties of Ce0.8Eu0.1M0.1O2−δ (M = Zr, Hf, La, and Sm) solid solutions towards soot combustion

The physicochemical properties of Ce–Eu-oxides were greatly improved by the introduction of trivalent or tetravalent metal cations into their lattice.