Selective Catalytic Reduction of NOx with NH3 by Using Novel Catalysts: State of the Art and Future Prospects

Lupeng Han; Sixiang Cai; Min Gao; Jun-Ya Hasegawa; Penglu Wang; Jianping Zhang; Liyi Shi; Dengsong Zhang

doi:10.1021/acs.chemrev.9b00202

Selective Catalytic Reduction of NO_x with NH₃ by Using Novel Catalysts: State of the Art and Future Prospects

Chem Rev. 2019 Oct 9;119(19):10916-10976. doi: 10.1021/acs.chemrev.9b00202. Epub 2019 Aug 15.

Authors

Lupeng Han¹, Sixiang Cai^{1

2}, Min Gao³, Jun-Ya Hasegawa³, Penglu Wang¹, Jianping Zhang¹, Liyi Shi¹, Dengsong Zhang¹

Affiliations

¹ Department of Chemistry, College of Sciences, State Key Laboratory of Advanced Special Steel, Research Center of Nano Science and Technology, School of Materials Science and Engineering , Shanghai University , Shanghai 200444 , China.
² School of Materials Science and Engineering , Hainan University , Haikou 570228 , Hainan , China.
³ Institute for Catalysis , Hokkaido University , Sapporo 001-0021 , Japan.

PMID: 31415159
DOI: 10.1021/acs.chemrev.9b00202

Abstract

Selective catalytic reduction with NH₃ (NH₃-SCR) is the most efficient technology to reduce the emission of nitrogen oxides (NO_x) from coal-fired industries, diesel engines, etc. Although V₂O₅-WO₃(MoO₃)/TiO₂ and CHA structured zeolite catalysts have been utilized in commercial applications, the increasing requirements for broad working temperature window, strong SO₂/alkali/heavy metal-resistance, and high hydrothermal stability have stimulated the development of new-type NH₃-SCR catalysts. This review summarizes the latest SCR reaction mechanisms and emerging poison-resistant mechanisms in the beginning and subsequently gives a comprehensive overview of newly developed SCR catalysts, including metal oxide catalysts ranging from VO_x, MnO_x, CeO₂, and Fe₂O₃ to CuO based catalysts; acidic compound catalysts containing vanadate, phosphate and sulfate catalysts; ion exchanged zeolite catalysts such as Fe, Cu, Mn, etc. exchanged zeolite catalysts; monolith catalysts including extruded, washcoated, and metal-mesh/foam-based monolith catalysts. The challenges and opportunities for each type of catalysts are proposed while the effective strategies are summarized for enhancing the acidity/redox circle and poison-resistance through modification, creating novel nanostructures, exposing specific crystalline planes, constructing protective/sacrificial sites, etc. Some suggestions are given about future research directions that efforts should be made in. Hopefully, this review can bridge the gap between newly developed catalysts and practical requirements to realize their commercial applications in the near future.