Design Sr, Mn-doped 3DOM LaCoO3 perovskite catalysts with excellent SO2 resistance for benzene catalytic combustion

Abstract

Anti SO2 poisoning is a major scientific challenge in the field of VOCs catalytic combustion. To enhance sulfur resistance of 3DOM LaCoO3 perovskite catalysts, the strontium (Sr) and manganese (Mn) elements were doped to regulate and control its microstructure and electronic valence states of active metals. The macropore structure is constructed to accelerate the adsorption and diffusion of benzene and intermediate species and promote the deep oxidation in ordered macropores. Surprisingly, we observed that the co-doping of Sr and Mn components resulted in the superior catalytic performance for benzene catalytic combustion. Especially, the sulfur resistance of LaCoO3 catalyst was significantly improved due to the doping of Sr and Mn species. Through various characterizations, it is discovered that the doping of Mn component in 3DOM LaCoO3 perovskite catalyst could promote the formation of active Co3+ species due to the excellent redox properties between Mn&+ and Co&+ species (Mn4++Co2+→Mn3++Co3+), while the co-doping of Sr and Mn elements could produce and form some new active species. On one hand, Sr and Mn may act as an electron promoter to increase the concentration of Co3+ and Oads. On the other hand, Sr and Mn can act as a structure promoter to enhance the specific surface area and promote the dispersion of active Co species. The research provides valuable reference for the development of highly efficient catalysts for the industrial degradation of benzene.