Catalytic properties of CeO₂/TiO₂ synthesized by different methods towards the organic dye photodegradation and NH₃ selected catalytic removal of NO_x

Abstract

In this work, three synthesis methods including photo-chemical, precipitation and hydrothermal were applied for synthesizing CeO2/TiO2 catalysts, and the catalytic performance including photodegradation degrees for organic pollutant and ammonia selective catalytic reduction (NH3-SCR) for NO removal were investigated. It was found that the photo-chemical synthesized CeO2-TiO2-PC exhibited the best photodegradation ability for methylene blue (MB), which had the degradation ratio of 91.21 % and was approximately 23.92 % higher than that with the matrix of rutile TiO2. The formed Ce-Ti heterojunction enhanced the separation of e-/h+ and further promoted the photocatalytic properties. Moreover, the CeO2-TiO2-PC, and the CeO2-TiO2-P which synthesized by the precipitation method showed better NH3-SCR properties than that of hydrothermal synthesized CeO2-TiO2-H below 300 oC, while the CeO2-TiO2-H owned an outstanding NH3-SCR performance above 300 oC. The difference on the NH3-SCR properties may be major attributed to the acid sites, pore structures and surface areas on the surface of different catalysts.