Low temperature selective catalytic reduction of NOx with NH3 over Mn-based catalyst: A review

AIMS Environmental Science

TsungYu Lee¹  Hsunling Bai¹ 

[1] Institute of Environmental Engineering, National Chiao Tung University, Hsinchu 300, Taiwan;

关键词: Selective catalytic reduction;    SO₂ resistance;    poisoning;    Fast SCR;    low temperature catalysts;   

DOI  :  10.3934/environsci.2016.2.261

来源: DOAJ

【 摘 要 】

The removals of NO_x by catalytic technology at low temperatures (100–300 °C) for industrial flue gas treatment have received increasing attention. However, the development of low temperature catalysts for selective catalytic reduction (SCR) of NO_x with ammonia is still a challenge especially in the presence of SO₂. The current status of using Mn-based catalysts for low temperature SCR of NO_x with ammonia (NH₃-SCR) is reviewed. Reaction mechanisms and effects of operating factors on low temperature NH₃-SCR are addressed, and the SCR efficiencies of Mn-based metal oxides with and without SO₂ poisoning have also been discussed with different supports and co-metals. The key factors for enhancing low temperature NH₃-SCR efficiency and SO₂ resistance with Mn-based catalysts are identified to be (1) high specific surface area; (2) high surface acidity; (3) oxidation states of manganese; (4) well dispersion of manganese oxide metals; (5) more surface adsorbed oxygen; (6) more absorbed NO₃⁻ on the catalyst surface; (7) easier decomposition of ammonium sulfates. Moreover, the regenerative methods such as water washing, acid and/or alkali washing and heat treatment to the poisoned catalysts could help to recover the low temperature SCR efficiency to its initial level.

【 授权许可】

Unknown