Ho掺杂对Mn-Ce/TiO_2低温SCR催化剂的脱硝性能影响

Influence of Ho doping on the deNO_x performance of Mn-Ce/TiO_2 low temperature SCR catalyst

采用浸渍法制备了五种掺杂不同比例的Ho的低温选择性催化还原(SCR)催化剂Mn0.4Ce0.07Hox/TiO_2。研究了Ho的引入对于Mn-Ce/TiO_2催化剂低温脱硝性能的影响,并采用XPS、XRF、BET、XRD、NH3-TPD等手段对催化剂的物理化学性质进行表征。结果表明,掺杂适量的Ho能够有效提高Mn-Ce/TiO_2催化剂的低温脱硝性能,当Ho/Ti掺杂比例为0.1时催化剂Mn0.4Ce0.07Ho0.1/TiO_2活性表现最佳,在200℃左右催化效率达到最高,为91.17%,在140-240℃催化效率达到80%以上。结果表明,Ho的掺杂能够增大催化剂的比表面积,提高催化剂化学吸附氧的浓度以及Ce的附着量。

A series low temperature SCR catalysts Mn0.4 Ce0.07 Hox/TiO2 catalysts with different Ho doping ratios were prepared by impregnation method. The effects of Ho doping on the denitrification of Mn-Ce/TiO2 low temperature SCR catalyst were studied. The catalysts were characterized by using X-ray photoelectron spectroscopy（XPS）,X-ray fluorescence probe（XRF）,Brunauer-Emmett-Teller（BET） surface measurement,X-ray diffraction（XRD） and NH3-temperature programmed desorption（NH3-TPD）. The results showed that the doping of Ho can improve the low temperature denitrification performance of Mn-Ce/TiO2 catalyst. The catalytic efficiency of Mn0.4 Ce0.07 Ho0.1/TiO2 with the ratio of Ho： Ti = 0.1 reached 91.17% at 200 ℃,which is the highest during the process. The catalytic efficiency could reach more than 80% at 140-240 ℃. The characterization results showed that Ho doping can increase the surface area of the catalyst,increase the concentration of chemisorbed oxygen in the catalyst and increase the deposition amount of Ce on the catalyst surface.