Low-Temperature Performance of Pt/TiO₂ for Selective Catalytic Reduction of Low Concentration NO by C₃H₆

Abstract

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, O2/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 % O2, balanced with Ar, 0.5 wt % Pt loaded TiO2 calcined at 500 °C could achieve a complete C3H6 conversion and 47.03% NO x reduction simultaneously at 180 °C. This enhanced activity may be associated with its outstanding activities in the TPO processes of NO 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 °C was suggested to be responsible for such an enhancement. The research results also suggested that higher concentration of O2 and higher concentration of C3H6 favored NO removal, and Pt loading played an important role in the SCR process.

Hydrothermal Synthesis of a Pt/SAPO-34@SiC Catalytic Membrane for the Simultaneous Removal of NO and Particulate Matter

“…The results showed that the electron interactions generated between TiO 2 and the platinum nanoclusters protected the platinum from oxidation, and over 90% of NO can be degraded at a temperature of 250 °C. Liu et al employed a WO 3 -modified Pt/TiO 2 catalyst for the catalytic degradation of NO x and achieved an 88% NO x conversion rate due to the large amounts of adsorbed NH 4 + as well as the NO x species generated by Pt and WO 3 . Hu et al .…”

“…The results showed that the electron interactions generated between TiO 2 and the platinum nanoclusters protected the platinum from oxidation, and over 90% of NO can be degraded at a temperature of 250 °C. Liu et al 15 amounts of adsorbed NH 4 + as well as the NO x species generated by Pt and WO 3 . Hu et al 16 used a facile hydrothermal method to fabricate boron-doped graphenesupported Pt (Pt/BG) nanosheets, which were applied for the catalytic reduction of NO with H 2 .…”