Promotional effect of CeO2 on low-temperature selective catalytic reduction of NO by NH3 over V2O5-WO3/TiO2 catalysts

The addition of 3% of CeO2 improved the NH3 adsorption performance, the NO oxidation, low temperature NO conversion, and the sulfur and water-resistance of the V2O5-WO3/TiO2 catalyst, established a protective layer against catalyst poisoning. With the increase in the regeneration temperature and time, the deactivation rate gradually increased, and the layered filling could slow down the catalyst's overall deactivation rate. In addition, the BET, SEM, XRD, FT-IR, XPS, TG, H-2-TPR, and NH3-TPD results showed that the upper layer catalyst first contacted the SO2 and H2O in the flue gases, leading to the deposition of by-products containing NH4+ and SO42- at the highest level in this catalyst layer. Also, the decrease in the specific surface area and pore volume was most obvious. The experiment selected the NH4+ and SO42- deposition amounts as characteristic indices for judging the catalyst poisoning degree, and they also revealed the catalytic reaction path of the CeO2 on the surface of the V2O5-WO3/TiO2 catalyst. (C) 2020 Elsevier B.V. All rights reserved.