采用溶胶凝胶法和浸渍法制备了以陶瓷颗粒为骨架的纳米级V2O5-WO3/TiO2(C)催化剂,并用X射线衍射(X-ray diffraction,XRD)和扫描电子透镜(transmission electron microscopy,TEM)表征了催化剂的晶型和形貌。研究了TiO2凝胶热处理温度和WO3负载量等重要参数对催化剂在以NH3为还原剂的选择性催化还原(selectivecatalytic reduc-tion,SCR)系统中的反应温度窗口、抗硫性的影响。最后考察了催化剂在不同NH3/NO比、O2含量、空速等因素下的性能指标。结果表明,在260～420℃的温度范围内,以陶瓷为骨架的负载型纳米V2O5-WO3/TiO2催化剂具有较高的SCR催化活性,且性能稳定;TiO2以锐钛形式存在的催化剂表现出高的抗硫性能,而TiO2以锐钛和金红石混晶形式存在时,抗硫性能比较差,但硫的中毒是可逆的,可再生;WO3负载量的增加提高了催化剂的活性。
Pre-treatments of the viscose rayon based activated carbon fibers(ACFs) with acid(HNO3,H2SO4,HCl),alkali(NaOH) and steam were carried out to modify the surface characters of ACFs.The activities of ACFs for selective catalytic reduction(SCR) at lower temperature were tested.There is an increase in the content of functional group with oxygen on the surface of ACF and a decrease in micropore range for the ACF treated with HNO3.The new functional groups are formed for the ACF treated with H2SO4,HCl and NaOH,which can improve the activity of SCR,and an increase in micropore range for ACF treated with NaOH is found.However,the portion of mesopores increases but the catalytic activity of ACF decreases for the ACF treated with steam.
