Abstract
? 2022 Elsevier B.V.The SCR activity of MOx (M=Al, P, Si, Zr) promoted V2O5-WO3/TiO2 was investigated before and after sulfation. In situ IR spectroscopy indicated that the VOx active sites preferentially anchor on promoter generated surface hydroxyl. In situ Raman spectroscopy confirmed that all oxides are completely dispersed on the TiO2 surface. In situ NH3-IR spectroscopy showed that the oxides can increase the Lewis (AlOx and ZrOx) and Br?nsted (POx, SiOx, VOx, WOx and SOx) acid site concentrations. The SiOx and ZrOx promoters had little effect on NO conversion, while the AlOx and POx promoters and surface sulfation generally inhibited it. The SiOx promoted catalyst was highly SCR active despite lacking Lewis acid sites, indicating that they are not vital for SCR. The N2O formation activity of the catalyst was inhibited by surface sulfation and the promoters, correlating with the promoter and SOx induced increase in the Br?nsted acid sites’ strength.
NSTL
Elsevier