Low-temperature SCR of NO with propylene in excess oxygen over the Pt/TiO2 catalyst

A series of TiO2 supported catalysts with 0.5 wt% noble metal (Pt, Pd, Rh and Ru) were used for the low-temperature selective catalytic reduction (SCR) of NO with propylene in the presence of excess oxygen. Under an atmosphere of 150 ppm NO, 150 ppm C3H6 and 18 vol% O2 (GHSV 72,000 h−1), the Pt/TiO2 was found to be the most active catalyst giving a complete C3H6 conversion and 63% NOx reduction simultaneously at 140 °C. The enhanced activity of Pt/TiO2 may be associated to its outstanding activities in the temperature-programmed oxidation (TPO) of NO to NO2 and C3H6 to CO2.