Catalytic oxidation of toluene over the low-grade palygorskite clay from Linze region supported highly dispersed Mn-Ce oxides catalysts: Preparation and performance

The natural palygorskite clay (Pal) resources are widely distributed in the Tianshui-Jingyuan-Huining-Linze sedimentary basins from east to west, Gansu Province, Northwest China. However, the application of this Pal has received insufficient attention due to the low-grade of palygorskite and hybrid mineral assemblage. In this paper, the Linze Pal was used as the support to prepare a series of Mn-Ce/Pal catalysts for catalytic oxidation of toluene. The catalysts were characterized by XRD, BET, Raman, XPS spectroscopy and TEM analysis. The results indicated that the particle sizes of Mn oxides were decreased and the dispersions were improved after doping with cerium. The strong interaction between Mn and Ce oxides increased the specific surface area, the content of Mn3+ and Ce3+ and the surface-adsorbed oxygen species of the Mn-Ce/Pal catalysts with the decrease of doping amount of cerium, which had significant effect on the catalytic activities of the catalysts for toluene oxidation. The 5 %Mn0.9Ce0.1/Pal catalyst exhibited the best performance for toluene oxidation and had a T90 at 318 degrees C; meanwhile, this studied catalyst also displayed high long-term and regeneration stabilities. Therefore, this lowgrade palygorskite clay in Linze region can be considered as a potential support to prepare the catalysts for toluene conversion.