Low-temperature complete removal of toluene over highly active nanoparticles CuO-TiO2 synthesized via flame spray pyrolysis

Abstract

Exploration of high-efficiency catalysts is of great significance to low-temperature pollutant removal. However, limited loading of the active component onto supports has become one of the major obstacles to improving catalytic efficiency. Here, we prepare highly active CuO-TiO2 nanocatalysts (CuO mass ratio from 2 to 50 wt.%) via a one-step flame spray pyrolysis (FSP) method. The catalysts are applied to the elimination of 300 ppmv toluene. We found that 8–20 wt.% CuO loaded TiO2 exhibits complete oxidation at a temperature of 250 °C in the absence of water vapor, which is mainly attributable to its stable highly dispersed CuO, low temperature reducibility and highly specific surface area. The high activity of Cu species and oxide defects contributes to a synergistic effect on the overall performance, which is optimized at 20 wt.% CuO without water vapor and 8 wt.% CuO under 10 vol.% water vapor. Increased dispersion of the Cu species can better enhance VOC oxidation and abate the inhibition of water vapor.