The promoting/inhibiting effect of water vapor on the selective catalytic reduction of NOx

Rongrong Gui; Qinghua Yan; Tianshan Xue; Yanshan Gao; Yuran Li; Tingyu Zhu; Qiang Wang

doi:10.1016/j.jhazmat.2022.129665

The promoting/inhibiting effect of water vapor on the selective catalytic reduction of NO_x

J Hazard Mater. 2022 Oct 5:439:129665. doi: 10.1016/j.jhazmat.2022.129665. Epub 2022 Jul 22.

Authors

Rongrong Gui¹, Qinghua Yan², Tianshan Xue³, Yanshan Gao⁴, Yuran Li⁵, Tingyu Zhu⁵, Qiang Wang⁶

Affiliations

¹ Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
² Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, China.
³ Institute of Atmospheric Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
⁴ Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China. Electronic address: yanshan_gao@bjfu.edu.cn.
⁵ Research Center for Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
⁶ Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China. Electronic address: qiangwang@bjfu.edu.cn.

PMID: 35907283
DOI: 10.1016/j.jhazmat.2022.129665

Abstract

In the field of nitrogen oxides (NO_x) abatement, developing selective catalytic reduction (SCR) catalysts that can operate stably in the practical conditions remains a big challenge because of the complexity and uncertainty of actual flue gas emissions. As water vapor is unavoidable in the actual flue gas, it is indispensable to explore its effect on the performance of SCR catalysts. Many studies have proved that the effects of H₂O on de-NO_x activity of SCR catalysts were indeed observed during SCR reactions operated under wet conditions. Whether the effect is promotive or inhibitory depends on the reaction conditions, catalyst types and reducing agents used in SCR reaction. This review focuses on the effect of H₂O on SCR catalysts and SCR reaction, including promoting effect, inhibiting effect, as well as the effecting mechanism. Besides, various strategies for developing a water-resistant SCR catalyst are also included. We hope that this work can give a more comprehensive insight into the effects of H₂O on SCR catalysts and help with the rational design of water-resistant SCR catalysts for further practical application in NO_x abatement field.

Keywords: Impacting mechanism; SCR catalyst; SCR reaction; Water effect; Water resistance improvement.

Publication types

Review