Zr改性CeO_2/TiO_2催化剂选择性催化还原烟气脱硝性能

Performance of Zr modified CeO_2/TiO_2 catalyst for selective catalytic reduction of flue gas denitrification

采用Zr对CeO_2/TiO_2催化剂进行改性,考察Zr掺杂对CeO_2/TiO_2催化剂NH_3选择性催化还原NO性能的影响,利用静态N_2物理吸附、X射线衍射(XRD)、NH_3程序升温脱附(NH_3-TPD)和X射线光电子能谱(XPS)对其脱硝机制进行分析。结果表明,Zr掺杂能够拓宽CeO_2/TiO_2催化剂的温度窗口,提高其脱硝活性和抗H_2O/SO_2性能。Zr掺杂能够增大CeO_2/TiO_2催化剂的比表面积和总孔容,抑制载体锐钛矿TiO_2发生晶相转变,显著提高催化剂的表面酸性,增加催化剂表面Ce^(3+)和化学吸附氧的原子浓度,使得催化剂表面NH_3吸附能力加强,氧化还原能力提高,有助于促进SCR反应的进行。

Zr was used to modify the CeO2/TiO2catalyst.The effect of Zr doping on the selective catalytic reduction of NO with NH3over CeO2/TiO2catalyst was investigated and their deNOx mechanism was analyzed by the static N2physical adsorption,X ray diffraction(XRD),NH3temperature programmed desorption(NH3TPD),and X ray photoelectron spectroscopy(XPS).The results indicate that Zr doping could widen the temperature window of the CeO2/TiO2catalyst and improve its activity and resistance to H2O and SO2.Zr doping could enlarge the BET surface volume ratio and total pore volume of the catalyst,inhibit the transformation of crystalline phase of anatase TiO2carrier,markedly enhance the surface acidity and increase the concentration of Ce3+and chemisorbed oxygen on the catalyst surface.It could also enhance the ability to adsorb NH3and increase the redox ability,thereby promoting the SCR reaction.