Supported ultralow loading Pt catalysts with high H2O-, CO2-, and SO2-resistance for acetone removal

Abstract

Volatile organic compounds (VOCs) cause damage to atmospheric environment and human health. Supported noble metal catalysts are widely used to control VOCs emissions. The high cost, and low H2O-, CO2-, and SO2-resistance of such catalysts are worthy to be improved. Herein we fabricated Ce-, V-, or W-doped TiO2 supported ultralow loading Pt catalysts via the in-situ molten salt method, and evaluated their catalytic performance for acetone (major pollutants in pharmaceutical industry) removal. Under the present reaction conditions, all the catalysts exhibited high catalytic activity and stability for acetone oxidation, with the temperature required 90% acetone conversion being of 245 °C over 0.57 wt% CeO2-0.05 wt% Pt/TiO2. The doping of Ce, V, or W enhanced the H2O-, CO2-, and SO2-tolerance ability of 0.05 wt% Pt/TiO2. More than 85 %85%, 70%, or 60% of acetone could be removed even in the presence of 20 vol% water vapor, 10 vol% CO2, or 100 ppm SO2, respectively. The improvement in SO2-tolerance ability was due to the inhibition of SO2 adsorption and oxidation activity as well as Ti(SO4)2 or TiOSO4 formation. Acetone complete oxidation over 0.57 wt% CeO2-0.05 wt% Pt/TiO2 would follow the pathway: adsorbed acetone molecules → acetic acid and formic acid → carbonate species → CO2 and H2O. The present supported Pt catalysts might be suitable for oxygenated VOCs removal.