A study of selective catalysis reduction denitration performance and adsorption of NH3 and NO over γFe2O3 catalys

作者：Liang Hui^*; Zha Xianbin; Gui Keting

来源：Proceedings of the CSEE, 2014, 34(32): 5734-5740.

DOI：10.13334/j.0258-8013.pcsee.2014.32.006

• Adsorption of no
• Catalysts surface
• Catalytic reactions
• Fixed bed reactor
• High thermal stability
• Intermediate product
• Selective catalysis reduction (SCR)
• Situ diffuse reflectance infrared Fourier transform spectroscopy

The catalyst used for selective catalysis reduction (SCR) of NOx was prepared from γFe2O3 nanoparticles and characterized by XRD and BET methods. The catalytic experiments at low temperature were carried out in a fixed bed reactor. The adsorption and activation of NH3 and NO on γFe2O3 nano-catalyst were investigated by in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) measurement. Results showed that Fe2O3 used for catalytic reaction was pure maghemite phase with high thermal stability, and exhibited a high low-temperature denitration performance. The DRIFTS experiments showed that NH3 was mainly adsorbed on Lewis acid sites to form coordinated NH3, while partial NH3 was adsorbed on Brønsted acid sites to form ammonium at the temperature below 270. O2 promoted the dehydrogenation of coordinated NH3 to form amide species. O2 greatly enhanced the adsorption of NO on catalysts surface to form nitrate species and absorbed NO2. Two possible reaction paths on γFe2O3 catalyst were proposed. The SCR process mainly follows that NH2 formed by H-abstraction of coordinated NH3 reactes with NO to form N2 and H2O. In a relative low temperature range (⟨240), another reaction path follows that NO2(NH4+)2 as the key intermediate product reactes with NO to form N2, H2O and H+.

• 出版日期2014
• 单位东南大学