Recent advances in layered double hydroxides (LDHs) derived catalysts for selective catalytic reduction of NOx with NH3

Qinghua Yan; Xiangting Hou; Guocheng Liu; Yuran Li; Tingyu Zhu; Yanjun Xin; Qiang Wang

doi:10.1016/j.jhazmat.2020.123260

Recent advances in layered double hydroxides (LDHs) derived catalysts for selective catalytic reduction of NO_x with NH₃

J Hazard Mater. 2020 Dec 5:400:123260. doi: 10.1016/j.jhazmat.2020.123260. Epub 2020 Jun 21.

Authors

Qinghua Yan¹, Xiangting Hou¹, Guocheng Liu¹, Yuran Li², Tingyu Zhu², Yanjun Xin³, Qiang Wang⁴

Affiliations

¹ Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, PR China.
² Research Center for Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China.
³ Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, PR China. Electronic address: xintom2000@126.com.
⁴ College of Environmental Science and Engineering, Beijing Forestry University, 35 Qinghua East Road, Haidian District, Beijing 100083, PR China. Electronic address: qiangwang@bjfu.edu.cn.

PMID: 32947694
DOI: 10.1016/j.jhazmat.2020.123260

Abstract

In recent years, layered double hydroxides (LDHs) derived metal oxides as highly efficient catalysts for selective catalytic reduction of NO_x with NH₃ (NH₃-SCR) have attracted great attention. The high dispersibility and interchangeability of cations within the brucite-like layers make LDHs an indispensable branch of catalytic materials. With the increasingly stringent and ultra-low emission regulations, there is an urgent need for highly efficient and stable low-medium temperature denitration catalysts in markets. In this contribution, we have critically summarized the recent research progress in the LDHs derived NH₃-SCR catalysts, including their ability for NO_x removal, N₂ selectivity, active temperature window, stability and resistance to poisoning. The advantages and defects of various types of LDHs-derived catalysts are comparatively summarized, and the corresponding modification strategies are discussed. In addition, considering the importance of the catalyst's resistance to poisoning in practical applications, we discuss the poisoning mechanism of each component in flue gases, and provide the corresponding strategies to improve the poisoning resistance of catalysts. Finally, from the perspective of practical applications and operation cost, the regeneration measures of catalysts after poisoning is also discussed. We hope that this work can give timely technical guidance and valuable insights for the applications of LDHs materials in the field of NO_x control.

Keywords: Hydrotalcite; Layered double oxides (LDOs); NH(3)-SCR; Regeneration; Resistance to poisoning.

Publication types

Review