Low-temperature selective catalytic oxidation of ammonia over the CuO x /C-TiO2 catalyst

Abstract

Carbon-coated TiO2 (C-TiO2) was synthesized by nano-anatase powders and absolute alcohol with chemical vapor deposition method in nitrogen (N2) atmosphere. The CuO x /C-TiO2 composite was prepared as a catalyst for the selective catalytic oxidation (SCO) of ammonia (NH3) and demonstrated both high catalytic activity and low NO yield. Microstructures and properties of these materials were characterized by X-ray diffraction, transmission electron microscopy, and Raman spectra (Raman). The catalytic activity for NH3 oxidation was promoted by introducing carbon into TiO2. NH3 oxidation efficiencies of 44 and 74 % could be obtained at 175 and 200 °C, respectively, under a gas hourly space velocity of 76,000 h−1. The CuO x /C-TiO2 composite was shown with higher catalytic activities than the CuO x /TiO2 catalyst because of the finer CuO x particles and CuO x species by the presence of the carbon layer. The C-TiO2 was a very favorable support for the SCO of NH3 at low temperature.