The influence of Ce doping on catalytic oxidation of toluene over Co3O4/iron mesh monolithic catalyst

In this paper, CeCoOx/iron mesh monolithic catalyst (CeCoOx/IM) was successfully prepared by hydrothermal method. The preparation conditions such as Ce/Co ratio, hydrothermal temperature as well as nitrate/urea ratio of the catalysts were optimized systematically. The catalytic performance results showed that when the Ce/Co ratio was 0.4, hydrothermal temperature was 160 °C and nitrate/urea ration was 1:8, the obtained catalyst possessed the best toluene oxidation activity, and the temperature at 50% and 90% toluene conversion (T50% and T90%) was 248 °C and 256 °C, respectively, which was lower than that of Co3O4/IM (260 °C and 267 °C, respectively). In addition, the active component is closely combined with the iron substrate with an exfoliation rate of 0.07%. H2-TPR results showed that the existence of rich Co3+ species and the strong interaction between Co and Ce was one of the reasons for this improvement performance. The introduction of Ce can also improve the thermal stability, water resistance and cycling stability of the catalyst. The reaction kinetics analysis showed that the Ea value was significantly reduced by Ce doping, which reached to 71.3 kJ·mol−1 for the best performance catalyst. We hope this study can provide a theoretical support for the practical application of catalyst.