酸化顺序对V-Mo/Ti脱硝催化剂性能的影响

Influence of the sequence of acid-treatment on the catalytic performance of V-Mo/Ti De-NO_(x)catalyst

采用硫酸对V-Mo/Ti脱硝催化剂进行酸化,考察了酸化顺序对催化剂物理化学性能和脱硝性能的影响。采用X射线衍射(XRD)、N_(2)-吸附脱附、H_(2)-程序升温还原(H_(2)-TPR)、拉曼光谱、NH_(3)-程序升温脱附(NH_(3)-TPD)和O_(2)-程序升温脱附(O_(2)-TPD)对催化剂进行表征。并通过固定床微型反应器,对比了不同催化剂脱硝性能。结果表明,采用先酸化、后负载活性组分的制备方法,可以增加催化剂上的聚合钒含量,提升催化剂的表面酸性和化学吸附氧含量,从而增强催化剂的脱硝活性。然后,采用先负载活性组分、后酸化的方式所制备的催化剂,脱硝性能较V-Mo/Ti催化剂有了明显的降低。

V-Mo/Ti De-NO_(x)catalyst was treated with sulfuric acid before or after the impregnation of V and Mo.The physical chemistry properties of the catalysts were studied by XRD、N_(2)-adsorption,H_(2)-TPR,Raman,NH_(3)-TPD,and O_(2)-TPD methods.Besides,the denitrification performances of the catalysts were evaluated by a fixed-bed reactor.The results showed that the amount of the polymeric vanadate increased over the acid-treated catalyst when SO_(4)^(2-) was deposited first,which increased the acidity and the chemical adsorbed oxygen content.As a result,the catalytic performance of the catalyst was enhanced.However,impregnating the V-Mo/Ti catalyst with H_(2)SO_(4)solution may cause the decline of catalytic activity of the catalyst.