1. Shielding ceria based catalysts from SO2 poisoning in NH3-SCR reaction: Modification effect of acid metal oxides.
- Author
-
Cai, Yandi, Zhang, Bifeng, Yu, Haowei, Ji, Xiaoyu, Sun, Jingfang, Wang, Xizhang, Qian, Qiuhui, Li, Lulu, Liu, Annai, Tan, Wei, Gao, Fei, and Dong, Lin
- Subjects
- *
METALLIC oxides , *WATER gas shift reactions , *CERIUM oxides , *BRONSTED acids , *CATALYSTS , *SULFUR dioxide , *POISONING , *TUNGSTEN trioxide , *AMMONIUM sulfate - Abstract
Modifying CeO 2 with acid sites is a common strategy for designing efficient catalysts for the selective catalytic reduction of NO x by NH 3 (NH 3 -SCR of NO x). However, the effect of acid metal oxide modification on the SO 2 resistance of CeO 2 has not been well revealed. In this work, it was found that the SO 2 resistance of CeO 2 modified with several acid metal oxides (i.e. , MoO 3 , WO 3 and Nb 2 O 5), followed an order of Mo/CeO 2 ≥ W/CeO 2 > Nb/CeO 2. Further systematic characterizations revealed that Mo-OH and W-OH on CeO 2 as Brønsted acid sites could better inhibit the SO 2 adsorption and the sulfation of active sites than highly dispersed NbO x mainly as Lewis acid sites because NH 4 + coordinated to Brønsted acid sites could help trap SO 2 to form ammonium sulfates rather than metal sulfates. The findings in this work provided important guidance for the design of efficient catalysts with superior SO 2 resistance performance. [Display omitted] • CeO 2 modified with varying acid metal oxides showed different resistance to SO 2. • Highly dispersed MoO 3 or WO 3 could better shield CeO 2 from SO 2 poisoning than Nb 2 O 5. • Mo and W sites as Brønsted acid sites could better inhibit the SO 2 adsorption on CeO 2. • SO 2 could interact with both highly dispersed Nb 2 O 5 and CeO 2 on Nb/CeO 2. • A strategy for designing efficient catalysts with superior resistance to SO 2 was provided. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF