载体改性对Fe-Mn/AC低温选择性还原催化剂脱硝性能的影响

Influence of Support Modification of Fe-Mn/AC Catalyst on the Denitration Performance in Selective Catalytic Reduction at Low Temperature

以经硝酸、柠檬酸、氧等离子体改性的活性炭(AC)和未改性活性炭为载体,以Fe、Mn为活性组分,采用等体积浸渍法制备了一系列Fe-Mn/AC催化剂。采用N 2物理吸附、傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、X射线光电子能谱(XPS)等手段对催化剂进行了表征,研究了载体改性对Fe-Mn/AC催化剂脱硝性能的影响。结果表明:所研究的载体改性方法主要是通过调控活性炭表面含碳氧双键官能团的数量来改善NH 3的吸附特性,从而提高烟气低温选择性还原(SCR)反应的脱硝率;所研究的改性方法不会对Mn、Fe活性组分产生显著影响;硝酸和柠檬酸改性的Fe-Mn/AC催化剂在反应温度120℃和空速8000 h-1条件下,脱硝率均为95%左右;柠檬酸可以替代硝酸,用于低温SCR催化剂载体活性炭改性,从而便于工业生产。

A series of Fe-Mn/AC catalysts were prepared by impregnation method with nitric acid,citric acid and oxygen plasma activated carbon and unmodified activated carbon as the carrier.The catalysts were characterized by N 2 physical adsorption,Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).Effects of modification method on the denitrification performance of Fe-Mn/AC catalyst were studied.Results show that the modification method mainly improves the adsorption characteristics of NH 3 by altering the number of C=O functional groups on the surface of activated carbon,thereby improving the low-temperature selective catalytic reduction(SCR)performance in denitrification reaction,without significant impact on active component Mn and Fe.The Fe-Mn/AC catalysts modified by nitric acid and citric acid have denitration rate about 95%at reaction temperature 120℃and space velocity 8000 h-1.Hence,citric acid can be used for activated carbon modification instead of nitric acid to facilitate industrial production.