Preparation of CeXMn1−XO2 Catalysts with Strong Mn-Ce Synergistic Effect for Catalytic Oxidation of Toluene

Abstract

A series of Ce-doped α-MnO2 catalysts (CeXMn1−XO2, x = 0.04, 0.07, 0.10) were synthesized by a simple in situ hydrothermal method. It was confirmed by characterization methods such as XRD, Raman, N2 adsorption–desorption and SEM confirmed that the introduction of Ce significantly regulated the microstructure of α-MnO2, specifically manifested as the reduction in grain size, the increase in defect sites, the increase in Mn-O bond length and altered morphological structure. H2-TPR, O2-TPD and XPS analyses further revealed the strong interaction between Mn and Ce, accompanied by significant electron transfer (Ce3+ + Mn4+ → Ce4+ + Mn3+), thereby promoting the formation of Mn3+ species. In the test of toluene catalytic oxidation performance, Ce0.07Mn0.93O2 exhibited the most excellent catalytic activity (T100 = 280 °C), while also having good thermal stability and water resistance. Furthermore, the degradation pathways of toluene were analyzed by TD-GC-MS technology: Toluene → Benzene → Benzaldehyde → Maleic anhydride → CO2 and H2O.