工业钛钨粉制备选择性催化还原催化剂的对比研究

Comparative study on SCR catalysts prepared from industrial titanium tungsten powder

以国产和进口专用于制备脱硝选择性催化还原(selective catalytic reduction,SCR)催化剂的工业钛钨粉为原料,采用浸渍法在不同条件下制备了V2O5-WO3/TiO2催化剂,测试了催化剂的脱硝性能,并且采用低温N2吸附法、X射线衍射(XRD)和扫描电子显微镜/X-射线能谱(SEM/EDX)对其结构和组成进行了表征,为提高国产钛钨粉的质量提供依据。实验结果表明,相同条件下国产钛钨粉制备的催化剂脱硝性能稍差于进口,其原因除了原料组成之外,还在于国产钛钨粉制备的催化剂孔容低于进口,活性组分的负载量较低;国产的钛钨粉中有少量的金红石,而且晶粒度较小,烧结程度较进口的大。提高国产钛钨粉的质量,除其组成适当外,还应考虑增大孔容,避免金红石的形成。

In order to improve the quality of domestic industrial titanium tungsten powder （WO3/TiO2）, VzOs-WO3/TiO2 DeNOx selective catalytic reduction （SCR） catalysts were prepared by the impregnation method under different conditions using domestic and imported industrial titanium tungsten powder as raw materials. DeNOx performance was tested. And the structure and composition of the as-prepared catalysts were characterized by low-temperature N2 adsorption, X ray diffraction （XRD） and scanning electron microscopy with Energy-Dispersive X-Ray （SEM/EDX） analyzing system, respectively. The experiment results demonstrated that the DeNOx performance of catalysts prepared by domestic titanium tungsten powder was slightly worse than the imported ones under the same preparation conditions. Besides the composition of domestic titanium tungsten powder, the smaller the pore volume, a small amount ofrutile existed in the domestic titanium tungsten power, the lower loading amount of active component V2O5, smaller grain size and greater sintering degree of the catalysts prepared by domestic titanium tungsten powder, were responsible for their poorer DeNOx performance. To increase domestic titanium tungsten powder quality, not only its appropriate composition （such as higher amount of WO3）, but also its pore volume and anatase phase should be considered.