Promoting effect of Ce added to metal oxide supported on Al pillared clays for deep benzene oxidation

Al pillared clays (Al-PILC) were used to support transition metals (M = Cr, Mn, Fe, Co, Ni and Cu) and Ce for the deep oxidation of low concentration of benzene. The effect of Ce addition to M/Al-PILC was also investigated. The catalysts were characterized by X-ray powder diffraction, N2 adsorption and H2 temperature programmed reduction techniques. Introduction of Ce into M/Al-PILC improves dispersion of transition metals, changes the redox properties of metal oxide and makes it easier to be reduced by the interaction between the two oxides, increasing lattice oxygen lability. In activity tests Mn based catalysts were observed to be the most active among the transition metals, and adding Ce obviously improved the activity and stability of M/Al-PILC. Moreover, Ce content had a great effect on the activity of MnCe/Al-PILC. MnCe (18:1)/Al-PILC exhibited the highest activity, and the temperature for complete benzene conversion using this catalyst was about 310 °C.