Effect of Vanadium and Tungsten Loadings on the Surface Characteristics and Catalytic Activities of V2O5-WO3/TiO2 Catalysts
钒和钨负载量对V2O5-WO3/TiO2表面形态及催化性能的影响

V2O5-WO3/TiO2 catalysts with different vanadium and tungsten loadings were prepared by impregnation method. The activities of selective catalytic reduction (SCR) of NO with NH3 were measured and surface characteristics of those samples were characterized. It is found that both the surface areas and catalytic activities are influenced by vanadium loadings. When the vanadium loadings increased from 1% to 8%, the catalyst surface areas decreased by 16 m2/g, while the highest activity temperature was reduced by about 100 degrees C. Tungsten acts as stabilizer and promoter of the SCR catalyst. When the vanadium loading was 1%, an increase of tungsten loadings from 0 to 6% resulted in the decrease of the catalyst surface areas by only 3 m2/g, while the activity window was expanded to both high and low temperature range each by about 50 degrees C. Vanadium and tungsten loadings have an effect on the surface VOx, but do not change the surface crystal structure of the catalysts.