Low temperature SCR de-NOx performance and mechanism of heteropolyacid VPO-Cr-PEG/TiO2 catalyst

In this paper, a heteropolyacid catalyst VPO-Cr-PEG/TiO2 was developed and the low temperature de-NOx performance of catalyst was studied. The experimental results showed that the de-NOx efficiency reached over 98% at the low temperature of 150–350 °C. The catalyst exhibited excellent sulfur and water resistance in the presence of 1000 ppm SO2 and 8 vol% H2O. In the presence of polyethylene glycol (PEG), the crystal surface energy of the catalyst decreased, and (VO)2P2O7 was the main active crystal phase of the catalyst. The selective catalytic reduction of NOx by NH3 over VP(1/5)O-Cr-PEG/TiO2 catalyst simultaneously followed the Langmuir-Hinshelwood and Eley-Rideal mechanisms.