V2O5-CuO/TiO2催化剂中低温选择性催化NOx还原研究

Selective catalytic reduction of NOx on V2O5-CuO/TiO2 catalyst at middle-low temperature

  • 摘要: 浸渍法制备了一系列V2O5-CuO/TiO2催化剂,考察中低温(200~300℃)条件下,以氨为还原剂选择性催化还原NOx的活性,并利用比表面积及微孔孔隙分析仪(BET)、X射线衍射(XRD)对催化剂进行微观表征和分析。结果表明,500℃焙烧的2V16Cu/TiO2催化剂展示了最佳的中低温催化活性和较宽的活性温度范围,在空速6.0×104 h-1、225℃条件下,NOx转化率达97.3%,250℃时达到100%,温度升至300℃,催化活性仍保持在100%。XRD结果表明,随着Cu负载量的增加,逐渐显现CuO的特征峰。结合活性评价数据说明,CuO是VCu/TiO2催化剂的主要活性组分之一,是降低SCR催化反应温度的重要因素。BET结果表明,CuO的负载对钒钛催化剂的表面结构有较大影响。耐硫性实验结果表明,添加钒氧化物制备的2V16Cu/TiO2催化剂的抗硫性能有所改善。

     

    Abstract: In this paper, a series of TiO2 supported vanadium pentoxide and copper oxide catalysts were prepared by the impregnation method for selective catalytic reduction of NOx with NH3 at middle-low temperature (200~300℃). The catalysts were characterized by BET and X-ray diffraction (XRD). The results showed that 2V16Cu/TiO2 calcinated at 500℃ exhibited the best catalytic activity at middle-low temperature and quite wide temperature window. A 97.3% NOx conversion was obtained at 225℃ and a gross hourly space velocity (GHSV) of 6.0×104h-1, and it reached 100% at 250~300℃. XRD results showed that the characteristic peak of CuO gradually emerged with the increase of CuO loading. CuO was the key active component of the VCu/TiO2 catalysts, and affected the catalytic activity at middle-low temperature significantly. The BET results showed that the CuO loading had great influence on surface structure of vanadium-titanium catalyst. The test of sulfur resistance performance showed that 2V16Cu/TiO2 which was prepared by the introduction of vanadium pentoxide improved its sulfur resistance performance slightly.

     

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