改性菱铁矿催化剂的催化脱硝活性及抗硫性研究

Catalytic denitration activity and sulfur resistance of modified siderite catalysts

  • 摘要: 采用混合搅拌法制备了Ce、Zr掺杂改性的菱铁矿SCR脱硝催化剂,研究了Ce、Zr共同掺杂对催化剂催化脱硝性能及抗硫性的影响。结果表明,3% Ce+3% Zr掺杂菱铁矿催化剂(Ce0.03/Zr0.03-菱铁矿)具有优异的催化脱硝活性,在180-330 ℃,催化脱硝效率均在92%以上,该催化剂同时具有良好的抗SO2性能,在210 ℃下通入体积分数为0.01%的SO2,8 h后仍有95%以上的催化脱硝效率。通过XRF、BET、XRD、NH3-TPD、TG等实验手段对催化剂成分、微观孔结构、晶相等进行表征。表征结果显示,Ce、Zr的掺杂能明显提高催化剂的比表面积以及表面结晶分散度,增强催化剂的表面酸性,促进硫酸铵盐在催化剂表面的分解。因此,催化剂具有优异的中低温催化脱硝活性及抗硫性。

     

    Abstract: The siderite denitration catalysts modified by Ce and Zr were prepared by mixing and stirring method. The effects of Ce and Zr co-doping on the catalytic denitration performance and sulfur resistance of the catalyst were studied. The results show that the 3%Ce+3%Zr-doped siderite catalyst(Ce0.03/Zr0.03-siderite) has the highest catalytic denitration activity and good sulfur resistance. The catalytic denitration efficiency is above 92% in the temperature range of 180-330 ℃. Furthermore, the denitration efficiency is still more than 95% after introducing SO2 gas with a volume fraction of 0.01% for 8 h at 210 ℃. The characteristics of the catalyst, such as components, microporous structure and crystal phase were determined by XRF, BET, XRD, NH3-TPD, TG and other experimental means. The characterization results show that the doping of Ce and Zr can significantly improve the specific surface area and surface crystal dispersion of the catalyst, enhance the surface acidity of the catalyst, and promote the decomposition of ammonium sulfate on the catalyst surface; thus the modified siderite catalyst has an excellent low-temperature catalytic denitration activity and a good sulfur resistance.

     

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