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

Abstract

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 NOX 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 % NOX conversion at 180 °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 NOX.