Enhanced catalytic performance of F-doped CeO2-TiO2 catalysts in selective catalytic reduction of NO with NH3 at low temperatures

摘要

The objective of this study was to investigate the promoting effect of F-doping of CeO2-TiO2 catalysts on low-temperature selective catalytic reduction (SCR) of NO (X) with NH3. A series of F-doped Ce-Ti mixed-oxide catalysts were prepared by the co-precipitation method. The experimental results showed that the best F-doped Ce-Ti mixed-oxide catalyst, with an F loading of 1.5 %, resulted in almost 97 % NO (X) conversion at 180 A degrees C. The catalysts were characterized by X-ray diffraction, Brunauer-Emmett-Teller analysis, X-ray photoelectron spectroscopy, and temperature-programmed desorption of NH3. The high activity might be because of F-induced strong interaction between Ce and Ti facilitating formation of Ce3+, which was important for improving chemisorption of oxygen. Addition of F could enhance the redox potential, resulting in more active adsorbed NH3 species, which simultaneously enhanced catalytic activity for NH3-SCR of NO (X) .