A novel CNTs functionalized CeO2/CNTs-GAC catalyst with high NO conversion and SO2 tolerance for low temperature selective catalytic reduction of NO by NH3

Yijuan Pu; Pengchen Wang; Wenju Jiang; Zhongde Dai; Lin Yang; Xia Jiang; Zhicheng Jiang; Lu Yao

doi:10.1016/j.chemosphere.2021.131377

A novel CNTs functionalized CeO₂/CNTs-GAC catalyst with high NO conversion and SO₂ tolerance for low temperature selective catalytic reduction of NO by NH₃

Chemosphere. 2021 Dec:284:131377. doi: 10.1016/j.chemosphere.2021.131377. Epub 2021 Jun 28.

Authors

Yijuan Pu¹, Pengchen Wang¹, Wenju Jiang², Zhongde Dai², Lin Yang², Xia Jiang², Zhicheng Jiang³, Lu Yao⁴

Affiliations

¹ College of Architecture and Environment, Sichuan University, Chengdu, 610065, PR China.
² College of Architecture and Environment, Sichuan University, Chengdu, 610065, PR China; National Engineering Research Center for Flue Gas Desulfurization, Chengdu, 610065, PR China.
³ Department of Biomass Science and Engineering, Sichuan University, Chengdu, 610065, PR China.
⁴ College of Architecture and Environment, Sichuan University, Chengdu, 610065, PR China; National Engineering Research Center for Flue Gas Desulfurization, Chengdu, 610065, PR China. Electronic address: yaolu@scu.edu.cn.

PMID: 34225121
DOI: 10.1016/j.chemosphere.2021.131377

Abstract

Low-temperature selective catalytic reduction of NO_x by NH₃ (NH₃-SCR) for diminishing SO₂ poisoning remains an issue in flue gas denitrification (DeNO_x). Herein, A novel CNTs functionalized low temperature NH₃-SCR catalyst CeO₂/CNTs-GAC was prepared, which showed high NO conversion activity (100% at 150 °C) and SO₂ resistance. The addition of CNTs restrained SO₂ adsorption but improved the selective adsorption of NO, which restricted the deposition of (NH₄)₂SO₄ and/or Ce₂(SO₄)₃, and resulted in high SO₂ resistance. The addition of CNTs facilitated the diffusion and transportation of NH₃ and NO, and the electron transfer on CeO₂/CNTs-GAC, leading to higher content of Ce³⁺ and adsorbed O species on the CeO₂/CNTs-GAC surface and promoted formation of surface-adsorbed oxygen O_A. Therefore, CeO₂/CNTs-GAC provided abundant NO adsorption and activation sites, facilitating "fast SCR" reaction and enhancing the NH₃-SCR reaction. The proposed CeO₂/CNTs-GAC catalyst exhibited higher NH₃-SCR activity, N₂ selectivity, catalytic durability and SO₂ resistance than CeO₂/GAC.

Keywords: CNTs; GAC; Low temperature NH(3)−SCR; Nitrogen oxides; SO(2) poisoning.

MeSH terms

Adsorption
Ammonia*
Catalysis
Cerium*
Oxidation-Reduction
Temperature

Substances

Cerium
Ammonia