Thermo-photocatalytic degradation of benzene on Pt-loaded TiO2/ZrO2

A TiO2/ZrO2 powder was prepared using TiOSO4 and ZrOCO3 through a homogeneous co-precipitation process. The Pt-loaded TiO2/ZrO2 catalyst was obtained by loading Pt onto the powder via an incipient wetness approach. The catalyst samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, degree of dispersion, N-2 adsorption-desorption (BET) and X-ray photoelectron spectroscopy (XPS). It was found that the catalytic activity was significantly affected by Pt loadings, reduction temperatures and the reaction temperatures. A synergetic effect took place between photocatalytic and thermocatalytic reactions when benzene was engaged in the thermo-photocatalytic degradation. For 80 mg m(-3) benzene, the kinetic constant of thermo-photocatalysis was 1.26, 1.64, 2.15 and 2.93 times higher than these ones of single photocatalysis. when 90 degrees C, 120 degrees C, 150 degrees C and 180 degrees C was applied to the reaction, respectively. The rate constant at 150 degrees C, presented by the thermo-photocatalytic reaction, was 2 times higher than it was obtained from the photocatalytic reaction, under various experiment conditions. It was also found that, highly concentrated benzene, in a concentration of 1000 mg m(-3), was degraded effectively by thermo-photocatalysis and the mineralization rate reached 90.3% within 16h. The thermo-photocatalytic technique was considered to have practical application foreground in the degradation of highly concentrated benzene. (C) 2012 Elsevier B.V. All rights reserved.