Performance of Ti-pillared montmorillonite supported Fe catalysts for toluene oxidation: The effect of Fe on catalytic activity

In this study, TiO2-pillared montmorillonite (Ti-PILC) supported Fe catalysts were synthesized and used for the catalytic oxidation of toluene. The prepared catalysts were characterized by a combination of XRD, N-2 adsorption -desorption isotherms, XPS, H-2-TPR and NH3-TPD. The Fe introduction preserves the mesoporous structure and porosity of Ti-PILC. In the steady-state catalytic test and kinetic analysis, the toluene oxidation over studied catalysts follows the Mars-Van Krevelen mechanism. By the generation of strong acid sites and abundant surface oxygen species, Fe introduction obviously improves the catalytic activity of Ti-PILC for toluene oxidation. But with the increase of Fe content, the activity initially enhances, and then decreases. The effect of Fe species on the promoted toluene oxidation over Ti-PILC was discussed in view of reaction mechanism and above-mentioned variations of physicochemical properties. Furthermore, the Ti-PILC supported Fe catalysts display high stability and superior activity in the presence of water vapor, which present an applied interest. (C) 2016 Elsevier B.V. All rights reserved.