Enhanced Activity of Nb-modified CeO2/TiO2 Catalyst for the Selective Catalytic Reduction of NO with NH3

Received: March 18, 2018
Revised: May 25, 2018
Accepted: June 26, 2018
Download Citation: RIS|BibTeX|https://doi.org/10.4209/aaqr.2018.02.0059  

Cite this article:
Jiang, Y., Bao, C., Liu, S., Liang, G., Lu, M., Lai, C., Shi, W. and Ma, S. (2018). Enhanced Activity of Nb-modified CeO2/TiO2 Catalyst for the Selective Catalytic Reduction of NO with NH3. Aerosol Air Qual. Res. 18: 2121-2130. https://doi.org/10.4209/aaqr.2018.02.0059

HIGHLIGHTS

• CeNbTi showed the excellent activity at 250–450°C in the GHSV of 90,000 h^–1.
• The introduction of Nb enhanced the resistance to high GHSV, K₂O, H₂O and SO₂.
• The reasons contributing to its excellent deNO_x performance were proposed.

ABSTRACT

A series of CeO₂-Nb₂O₅/TiO₂ catalysts were prepared by an impregnation method and investigated for the selective catalytic reaction (SCR) of NO with NH₃. The 15 wt.% CeO₂–10 wt.% Nb₂O₅/TiO₂ catalyst (CeNbTi) exhibited the highest activity and resistance to a high gas hourly space velocity and K₂O. In the presence of H₂O and SO₂, it also showed better activity than the CeTi catalyst. The addition of Nb could improve the dispersion of CeO₂ and increase the amount of Ce³⁺ and chemisorbed oxygen species on the catalyst surface, which enhances the catalytic activity of CeTi. The superior SCR activity of CeNbTi might also be attributed to its high redox ability, the enhanced adsorption capacity of NH₃ species and the synergistic action between Ce, Nb and Ti species.

Keywords: Selective catalytic reduction; NO; NH3; CeO2-Nb2O5/TiO2; Impregnation method.