钒改性对铁基脱硝催化剂活性及抗碱性能的影响

Effect of Vanadium Modification on the Activity and Alkali Resistance of Iron-Based de-NO_(x) Catalyst

通过引入V物种对二氧化钛负载的铁基催化剂进行改性,制备出了FeV/TiO_(2)催化剂,并与未改性的铁基催化剂进行比较,通过X射线衍射(XRD)、拉曼光谱测试(Raman)、比表面积测试(BET)、紫外-可见-近红外漫反射光谱测试(UV-Vis-NIR)、氨气程序升温脱附(NH_(3)-TPD)以及氢气程序升温还原(H_(2)-TPR)等一系列测试对催化剂进行了表征。结果表明,引入V后的催化剂呈现出以FeVO_(4)为主相的状态,并存在大量的酸性位点而具有较强的表面酸性,Fe、V物种间的强相互作用大大提升了氧化还原性,因此催化剂低温活性得以显著提升且温度窗口大大拓宽。此外,催化剂的结构几乎不受碱中毒的影响,且在K中毒后仍能维持较强的表面酸性,具有良好的抗碱金属中毒性能。

The FeV/TiO_(2) catalyst was prepared by introducing V species to modify the iron-based catalyst,and the structures and performances were compared with the unmodified catalyst.The catalysts were characterized by means of XRD,Raman,BET,UV-Vis-NIR,NH_(3)-TPD and H_(2)-TPR.The results show that FeVO_(4) exists as the main phase in the catalyst after introducing V,and there were abundant acid sites to guarantee strong surface acidity.The strong interaction between Fe and V species also greatly enhance the redox ability.Therefore,the low-temperature activity is significantly improved and the temperature window is greatly widened.Moreover,the structure of the catalyst is hardly affected by alkali poisoning,and the catalyst could still maintain strong surface acidity after poisoning,resulting in good resistance to alkali metals.