화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.50, No.13, 7866-7873, 2011
Low-Temperature Performance of Pt/TiO2 for Selective Catalytic Reduction of Low Concentration NO by C3H6
Pt/TiO2 catalysts prepared by sol-gel and wetness impregnation methods were investigated for the selective catalytic reduction (SCR) of NO by C3H6 in the presence of excess oxygen. The characteristics of the prepared catalysts were analyzed through XRD, BET surface area, NO temperature programmed desorption (TPD), and NO/C3H6 temperature programmed oxidation (TPO). The effects of the crystalline phase of TiO2, O-2/C3H6 concentration, and Pt loading amount have been studied. It was found that when bare support was impregnated with the noble metal Pt, the NO removal efficiency increased significantly. In particular, under the condition of 150 ppm NO, 150 ppm C3H6, and 18 vol % O-2, balanced with Ar, 0.5 wt % Pt loaded TiO2 calcined at 500 degrees C could achieve a complete C3H6 conversion and 47.03% NOx reduction simultaneously at 180 degrees C. This enhanced activity may be associated with its outstanding activities in the TPO processes of NOx to NO2 and C3H6 to CO2. The pure anatase crystal form together with its relatively high specific surface area for TiO2 sample calcined at 500 degrees C was suggested to be responsible for such an enhancement. The research results also suggested that higher concentration of O-2 and higher concentration of C3H6 favored NO removal, and Pt loading played an important role in the SCR process.