Flame synthesized nanoscale catalyst (CuCeWTi) with excellent Hg0 oxidation activity and hydrothermal resistance.

Abstract In view of poor hydrothermal resistance of impregnation prepared catalysts (Cu5Ce5W9Ti-I), this paper aims to enhance thermal and hydrothermal resistance of Cu/Ce based catalysts for Hg0 oxidation via flame synthesis technology. The result found that the flame synthesis method could form nanoscale Cu10Ce10W9Ti-F particles with smaller lattice size (8–25 nm), more stable carrier structure and more oxygen vacancies. The inter-doping and inter-substitution of Ce, Cu and Ti oxides created more oxygen vacancies (Ce3+) and L -sites (O2−). Furthermore, the carrier TiO2 of Cu10Ce10W9Ti-F existed in form of highly thermostable rutile rather than anatase. High Hg0 oxidation efficiency (MOE) of 83.9–99.7% at 100–450 °C proved excellent oxidation activity of Cu10Ce10W9Ti-F catalyst. Moreover, the thermal and hydrothermal treatment (700 °C) only decreased MOE by less than 5% since L -sites kept fine thermostability of Cu10Ce10W9Ti-F. The flame synthesis was proven to be a promising catalyst preparation method to enhance thermal and hydrothermal resistance.