UV-LED Photocatalytic Oxidation of CO over the Pd/TiO2 Catalysts Synthesized by the Decomposition of Pd(acac)(2)

The Pd nanoparticles were deposited on the TiO2 surface via the thermal decomposition of palladium acetylacetonate (Pd(acac)(2)). The catalytic activity of Pd/TiO2 catalysts was investigated in the CO oxidation under ambient conditions both in the absence and presence of UV-LED irradiation. The effect of additional UV pretreatment of the catalyst on the activity in CO oxidation was also studied. The rate of CO oxidation under UV irradiation was 3.5 times higher than the rate of dark catalytic oxidation. The dark catalytic and photocatalytic oxidation rates were monotonically increased as the Pd content was increased up to 2 wt.%. A small size and narrow size distribution of Pd nanoparticles on the TiO2 surface were the reasons for a high activity in CO oxidation. Al2O3 and SiO2 were also employed for the Pd deposition to investigate the effect of semiconducting support. Pd/TiO2 had much higher CO oxidation rate under UV irradiation than the Pd/Al2O3 and Pd/SiO2 catalysts, which do not have photocatalytic activity. It indicates that in the case of the Pd/TiO2 catalysts UV light energy can be used instead of thermal energy to increase the rate of CO oxidation. (C) 2017 Elsevier Ltd. All rights reserved.