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

Ye Jiang,Changzhong Bao,Chengzhen Lai,Weiyun Shi,Guitao Liang,Mingyuan Lu,Shiyuan Ma,Shaojun Liu

doi:10.4209/aaqr.2018.02.0059

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.

Highlights

Selective catalytic reduction (SCR) of NOx with NH3 has been a dominant technique to remove NOx in the exhaust gas from stationary and mobile sources (Nakajima and Hamada, 1996; Busca et al, 1998; Du et al, 2018)
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 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

Summary

Introduction

Selective catalytic reduction (SCR) of NOx with NH3 has been a dominant technique to remove NOx in the exhaust gas from stationary and mobile sources (Nakajima and Hamada, 1996; Busca et al, 1998; Du et al, 2018). Tremendous attention has been paid to cerium-based oxides for the SCR of NO with NH3, such as CeO2/TiO2 (Xu et al, 2008; Gao et al, 2010b; Shan et al, 2011; Li et al, 2012), CeO2/Al2O3 (Shen et al, 2009; Guo et al, 2013), MnOx-NbOx-CeO2 (Chen et al, 2015), CeO2-MoO3/TiO2 (Liu et al, 2014; Jiang et al, 2015a), CeO2-WO3/TiO2 (Chen et al, 2010; Shan et al, 2012; Jiang et al, 2015b; Zhao et al, 2016) and NbOx/CeO2-ZrO2 (Ma et al, 2015). These observations motivated us to add niobium oxide to Ce/Ti catalyst to adjust its physicochemical properties, so as to enhance its SCR activity

Methods

Results

Conclusion