Ni(Mn,Cu)Ti-LDHs衍生催化剂低温NH3-SCR性能研究

采用尿素均相共沉淀法,将Cu、Mn原位掺杂进NiTi-LDH层板制备了NiCuTi-LDH和NiMnTi-LDH前驱体,经焙烧衍生构筑NiCuTi-LDO和NiMnTi-LDO催化剂,借助XRD,H2-TPR,NH3-TPD和XPS技术对催化剂进行表征,考察了Cu、Mn的引入对催化剂低温脱硝性能的影响。结果表明:相比于NiTi-LDO催化剂,Cu、Mn原位掺杂有效增加了催化剂中可还原物种的含量,提升了镍钛基催化剂的氧化还原能力,进而呈现出更好的低温SCR活性。NiCuTi-LDO催化剂在180~330℃范围内NOx转化率超过90%;NiMnTi-LDO催化剂进一步拓宽了活性温度窗口(在150~360℃范围内NOx转化率超过90%)。

Low temperature NH_3-SCR performances of Ni(Mn,Cu)Ti-LDHs derived catalysts

NiCuTi-LDH and NiMnTi-LDH precursors were prepared by in-situ doping of Cu and Mn into NiTi-LDH laminates by urea homogeneous co-precipitation method, which were calcined to obtain the NiCuTi-LDO and NiMnTi-LDO catalysts. The catalysts were characterized by XRD, H2-TPR, NH3-TPD and XPS, and the influence of the introduction of Cu and Mn on the low-temperature NH3-SCR performance of the catalysts were investigated. The results show that compared with the catalyst NiTi-LDO, in-situ doping of Cu and Mn effectively increases the content of reducible species in the catalysts, improves the redox behaviour of catalysts, and thus exhibits better low-temperature SCR activity. The NiCuTi-LDO has a NOx conversion of above 90% in 180-330℃, and the NiMnTi-LDO further widens the active temperature window with a NOx conversion of above 90% in 150-360℃.