Potassium promoted Fe–Ce composite oxides monolithic catalysts for catalytic soot combustion

In this work, the potassium promoted Fe–Ce composite oxides supported on the monolithic three-dimensional (3D) macroporous nickel foam substrates (KFeCe@NF) were synthesized by sequential wetness impregnation method and used for catalytic soot combustion. The best catalytic performance was obtained over K(0.1)FeCe@NF catalyst under 10%H₂O/800ppmNO/20%O₂/N₂ atmosphere using a wet contact mode and the lowest T₁₀, T₅₀ and T₉₀ values could reduce to 274 ℃, 313 ℃ and 353 ℃, respectively. A detailed comparison of the structural properties for the samples before and after potassium loading was conducted by XRD, FESEM, EDS and XPS. The addition of K could lead to reduction of partial Fe₂O₃ to FeO and make the Fe₂O₃ nanosheets transform into agglomerated nanoparticles. Moreover, the enhanced catalytic performance of KFeCe@NF for soot combustion is main due to the abundant active oxygen species inspired by the strong interaction between potassium and transition metal oxides.