Thermocatalytic oxidation of a three-component mixture of volatile organic compounds by a titanium dioxide-supported platinum catalyst

Abstract

To gain a better knowledge for efficient treatment of volatile organic compounds (VOCs), a series of experiments were carried out to assess the potential of titanium dioxide (TiO2)-supported platinum (Pt) catalyst (Pt/TiO2) in low-temperature catalytic oxidation of formaldehyde (FA), acetaldehyde (AA), and toluene (T) (10–100 ppm range) both individually and as a mixture. Accordingly, 100% mineralization of FA (50–200 ppm), AA (10 ppm), and T (10 ppm) was achieved by 1%-Pt/TiO2-R (‘R’ suffix for reduction pretreatment on the catalyst) at 30, 190, and 160 °C, respectively. The carbon dioxide (CO2) yield was used to assess the extent of VOC mineralization in air (as the carrier gas at a flow rate of 0.2 L atm min ̶ 1). Their conversion efficiency was lowered with increases in the pollutant concentration or decreases in the bed mass. Furthermore, the reaction intermediates and catalytic pathways were assessed based on in-situ diffuse reflectance infrared Fourier transform spectroscopy. This study offers valuable insights into the interactive roles between process variables in the low-temperature thermocatalytic oxidation of single and/or multi-component gaseous VOC systems and into the effects of such variables on the overall catalytic performance.