Sol–gel synthesis of CuO-TiO2 catalyst with high dispersion CuO species for selective catalytic oxidation of NO

Abstract

In this study, CuO-TiO2 (Cux-Ti) mixed-oxide catalysts with different Cu content prepared by sol-gel method were firstly used to selective catalytic oxidation (SCO) of NO. The catalytic activity test revealed that catalysts, especially Cu0.07-Ti, exhibited much higher catalytic performance than CuO supported TiO2 (Cu0.07/Ti) catalyst. XRD, EDS, Raman, XPS, H2-TPR, O2-TOD, NO-TPD and DRIFT measurements were used for characterizing the catalysts. The results of characterizations reveled that Cu0.07-Ti catalysts possessed high dispersed CuO. This feature of Cu0.07-Ti resulted in a strong interaction of Cu species with TiO2 support in compared to Cu0.07/Ti. This strong interaction not only enhanced amounts of active oxygen species by promoting the formation of oxygen vacancies, but also activated adsorbed NO over Cu0.07-Ti catalysts. In addition, on the basis of NO2 formation, it also promoted the decomposition of nitrate species to NO2 over Cu0.07-Ti catalyst. Based on the above mentioned favorable properties, Cu0.07-Ti catalysts had an excellent NO-SCO performance.