Cu/HZSM-5催化剂低温NH_(3)-SCR脱硝性能研究

Study on low temperature NH_(3)-SCR denitration performance of Cu/HZSM-5 catalyst

采用浸渍法制备Cu(x)/HZSM-5系列催化剂并应用于低温NH_(3)选择性催化还原脱硝性能研究。在固定床微型反应器上进行了O_(2)存在条件下催化剂的NH_(3)选择性催化还原NO活性评价,并通过XRD(X射线衍射仪),SEM(扫描电子显微镜),NO-TPD(程序升温脱附),O_(2)-TPD,TG-DSC-MS(热重-差示扫描量热法-质谱联用)等对催化剂性能进行表征。结果表明,催化剂的催化脱硝活性随着Cu负载量增加而逐渐增强,Cu负载量影响催化剂表面活性物种分布、氧化还原性能和吸附脱附性能,Cu以CuO的形式存在于催化剂表面或空隙中。Cu(6)/HZSM-5表现出较好的低温脱硝性能,与其拥有较好的氧化性能和NO吸附脱附性能等有关,159~378℃时NO的转化率接近100%。

Cu(x)/HZSM-5 catalyst is prepared by impregnation method and applied to the denitration performance study of NH_(3) selective catalytic reduction(NH_(3)-SCR)at low temperature.The NH_(3)-SCR denitration activity of the catalyst in the presence of O_(2) is evaluated in a fixed bed microreactor,and the performance of the catalyst is characterized by XRD,SEM,NO-TPD,O_(2)-TPD and TG-DSC-MS.The denitration activity of the catalyst increases gradually with the increase of Cu loading.Cu loading affects the surface active species distribution,redox and adsorption desorption performance of the catalyst.Cu exists on the surface or voids of the catalyst in the form of CuO.Cu(6)/HZSM-5 shows good low-temperature denitration performance which is related to its good oxidation performance and NO adsorption and desorption performance.The conversion of NO is close to 100%at 159~378℃.