采用浸渍法(IM)与溶胶凝胶法(Sol-gel)制备VMoTi催化剂,并在实验室模拟选择性催化还原(SCR)催化剂的碱金属K中毒,通过X射线衍射、BET比表面积测试法、NH3-程序升温脱附(TPD)、H2-程序升温还原(TPR)和光电子能谱等方法对催化剂表面的理化性能进行分析,并探讨钒钛系催化剂的反应及失活机理.结果 表明:与浸渍法制备的VMoTi催化剂相比,溶胶凝胶法制备的VMoTi催化剂具有较小的晶粒粒径,较大的比表面积和孔容,较多的表面酸量,较强的氧化还原能力以及较高的V4+、Mo4+和表面活性氧含量,因此,VMoTi (Sol-gel)催化剂表现出了较好的脱硝效率,在180～320℃的温度区间内,脱硝效率稳定在约100％.钾的加入会导致催化剂中毒,且不同方法制备的催化剂的中毒效应不同,K盐沉积对浸渍法制备的VMoTi催化剂的脱硝效率影响较大,溶胶凝胶法制备的VMoTi催化剂具有较好的抗K金属中毒的性能.通过对催化剂的表征发现,K盐削弱了活性成分与载体间的相互结合作用,增强了锐钛矿型TiO2衍射峰的强度,降低了催化剂表面酸性及氧化还原性,同时催化剂表面的化学吸附氧及V4+、Mo4+等活性金属含量降低,这些因素是造成催化剂活性下降的主要原因.“,”VMoTi catalyst was prepared separately by impregnation method (IM) and sol-gel method,and the alkali metal K poisoning of the catalyst was simulated.The X-ray diffraction,BET specific surface area test,NH3-temperature programmed desorption (TPD),H2-temperature programmed reduction (TPR),and X-ray photoelectron spectroscopy (XPS) methods were used to analyze the physical and chemical properties of the VMoTi catalyst,and the reaction and deactivation mechanisms of the vanadium-titanium-based catalyst were discussed.The results show that compared with the catalyst prepared by IM,i.e.,VMoTi (IM) catalyst,the catalyst prepared by the sol-gel method,i.e.,VMoTi (Sol-gel) catalyst,has a smaller grain size,a larger specific surface area and pore volume,a larger amount of surface acid,a stronger redox capacity,and a higher content of V4+,Mo4+,and surface active oxygen.Therefore,VMoTi (Sol-gel) catalyst shows a good denitration efficiency stabilized at ～100％ in the temperature range of 180～320 ℃.The addition of potassium (alkali metal) leads to catalyst poisoning,and the poisoning effect of the catalysts prepared by different methods is different.The K salt deposition has a great influence on the denitration efficiency of the VMoTi (IM) catalyst.The VMoTi(Sol-gel) catalyst has good resistance to K poisoning.Through the characterization of the catalyst,it is found that K salt weakens the interaction between the active ingredient and the carrier,enhances the intensity of the diffraction peak of anatase TiO2,and reduces the acidity and redox of the catalyst surface.At the same time,the content of chemical adsorption of oxygen and active metals,such as V4+ and Mo4+,decreases.These factors are the main reasons of the catalyst inactivity.