La_2O_3掺杂对V_2O_5-WO_3/TiO_2催化剂SCR性能的影响

通过共沉淀法将La组分掺入到TiO_2载体中,采用浸渍法将V和W组分负载到La_2O_3-TiO_2复合氧化物上,制备出V2O5-WO3/La_2O_3-TiO_2催化剂。考察不同La_2O_3掺杂量对其NH3催化还原NO性能的影响,同时通过多种物理化学手段进行表征分析。XRD,NH_3-in situ DRIFTS,H_2-TPR,XPS和UV-vis DRS测试结果表明,元素La与Ti以La-O-Ti键相互作用,生成高度分散的镧物种,也使得TiO_2具有更好的热稳定性,但由于LaO_x物种与VO_x物种和WO_x物种之间的相互作用,降低了催化剂的氧化还原性和表面Brnsted酸数量,从而降低了其催化活性。

Effect of La2O3 Doping on SCR Performance of V2O5-WO3/TiO2 Catalyst

Lanthanum (La) component was doped on TiO2 supporter by co-precipitation method,and vanadium (V),tungsten (W) components were then doped on La2O3-TiO2 composite by impregnation method to prepare V2O5-WO3/La2O3-TiO2 catalyst.The effect of La2O3 doping amount on the performance of selective catalytic reduction of NO with NH3 for the obtained catalyst was investigated and various characterizations were employed to analyze the catalyst.Test results of XRD,NH3-in siru DRIFTS,H2-TPR,XPS and UV-vis DRS indicate that La is combined with Ti by La-O-Ti bonds,forming highly dispersed LaOx species which makes TiO2 more thermally stable.However,the redox properties and surface Brφnsted acid sites of the catalyst are decreased,which further lowers the catalytic activity,due to the interactions among LaOx,VOx and WOx.