摘要
采用自发沉积法、共沉淀法及浸渍法制备MnO_x/TiO_2催化剂,通过XRD、TEM、N2吸附-脱附、XPS、H_2-TPR、NH_3-TPD等一系列表征手段研究MnO_x/TiO_2催化剂的结构与性质,并考察MnO_x/TiO_2催化剂低温NH_3-SCR性能。结果表明,自发沉积法制备的MnO_x/Ti O2(s)催化剂具有完全非晶态结构,Mn和Ti之间存在强相互作用,较共沉淀法制备的MnO_x/TiO_2(c)及浸渍法制备的MnO_x/Ti O2(i)表现出更强的氧化还原能力。MnO_x/TiO_2(s)具有较高的比表面积、较多的表面酸量,有利于NH_3的吸附与活化。且表面高浓度的Mn4+离子及吸附氧,有利于将NO氧化为NO2,促进发生"fast-SCR"反应,进而使其表现出优异的低温脱硝性能。MnO_x/TiO_2(s)催化剂在150℃时NO的转化率高达92.8%,在150-350℃NO的转化率保持在90%以上,此外其还具备较强的抗H_2O和SO_2毒化能力。
MnOx/TiO2 catalysts were prepared by spontaneous deposition,co-precipitation and impregnation methods,respectively. The structure and properties of the MnOx/TiO2 catalysts were studied by means of XRD,TEM,N2 adsorption-desorption,XPS,H2-TPR and NH3-TPD. The activity of the catalysts in the selective catalytic reduction of NO was investigated. The results showed that the MnOx/TiO2（ s） catalyst prepared by the spontaneous deposition method had a completely amorphous structure and a strong interaction between Mn and Ti,showed stronger redox ability than other two catalysts. In addition,the MnOx/TiO2（ s） catalyst exhibited larger surface area,more surface acid sites,which were beneficial to NH3 adsorption and activation,as well as the high Mn4＋ and adsorbed oxygen content of catalyst surface,which could greatly enhance the activity for NO oxidation to NO2,as a result,facilitating the＂fast-SCR＂reaction. Thus,a superior denitrification activity was exhibited over MnOx/TiO2（ s） catalyst. For MnOx/TiO2（ s） catalyst,the conversion of NO reached 92.8% at150 ℃ and retained over 90% in the range of 150-350 ℃. Moreover,the MnOx/TiO2（ s） catalyst also showed strong resistance to H2O and SO2 poisoning.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2017年第8期993-1000,共8页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(21306089)
江苏省创新基金(SJLX15-0347)资助~~
关键词
自发沉积法
非晶态
低温NH3-SCR
抗H2O/SO2
spontaneous deposition method
amorphous phase
low-temperature selective catalytic reduction
H2O/SO2 resistance
