Fe-doped porous Co3O4 nanosheets with highly efficient catalytic performance for soot oxidation

A series of CoxFe1-x-PNS materials were synthesized at room temperature through the one-pot MgO-mediated method and were then used as catalysts for soot oxidation. Of all the catalyst samples prepared, the porous Co0.8Fe0.2-PNS nanosheets exhibited the highest catalytic performance for soot oxidation under both loose and tight contact modes. The 2D nanosheets provided a larger external surface area for contact between the catalyst and soot, and the porous structure was beneficial to the adsorption and diffusion of reactant gas. It was found that Fe was successfully doped in the lattice of Co3O4, and the mechanism regarding how Fe doping enhances intrinsic activity was investigated by a series characterization and DFT calculations. The results indicated that Fe doping made it easier to form oxygen vacancies and adsorb gaseous O2, which effectively improved the catalytic activity of soot oxidation. Hence, it is believed that the synergy between the well-defined porous nanosheets morphology and the properties induced by the doping of Fe resulted in better catalytic activity. This study also provided insight into the design of 2D transition metal oxides nanosheets as catalysts for soot oxidation.