Fe-Mn-CeOx/AC@CNTs催化剂低温协同去除NO和氯苯

Fe-Mn-CeOx/AC@CNTs Catalysts for the Simultaneous Removal of NO and Chlorobenzene in Low Temperature

摘要:

以活性炭@碳纳米管（AC@CNTs）为载体，通过浸渍法制备了Mn-CeOx/AC@CNTs催化剂，并考察了铁物种的引入对Mn-CeOx/AC@CNTs催化剂同时去除一氧化氮（NO）和氯苯（CB）活性的影响。利用SEM、XRD、Raman、FTIR、XPS、H2-TPR等方法对催化剂的理化性质进行了表征。结果表明，Mn物种进入CeO2的晶格中形成Mn-Ce固溶体促进氧空位的生成，而催化剂表面存在丰富的C—H基团和含氧基团有利于提高催化剂的低温催化活性。与Mn-CeOx(1:7)/AC@CNTs（n(Mn):n(Ce)=1:7）催化剂相比，Fe-Mn-CeOx(1:7)/AC@CNTs催化剂表面吸附氧的含量和酸位点数量显著增加，使其具有良好的氧化还原性能和表面酸性。Fe-Mn-CeOx(1:7)/AC@CNTs催化剂在整个温度窗口表现出最高的催化活性，其中，在225～300 ℃范围内，NO转化率达到90%以上，300 ℃时，CB转化率>90%。此外，当CB存在时，300 ℃时，Fe-Mn-CeOx(1:7)/AC@CNTs催化剂的NO转化率依然能达到95%。

Abstract:

The Mn-CeOx/AC@CNTs catalyst was prepared by impregnation method using carbon@carbon nanotubes (AC@CNTs) support. And the catalytic performance of the addition of Fe species to Mn-CeOx/AC@CNTs for the simultaneous nitrogen monoxide (NO) reduction and chlorobenzene (CB) oxidation were investigated. The physical and chemical properties of the catalyst were characterized by SEM, XRD, Raman, FTIR, XPS, H2-TPR, and other methods. The results show that the introduction of Mn species into CeO2 with a large ionic radius, which forms a Mn-Ce solid solution and promotes the generation of oxygen vacancies, and abundant C—H groups and oxygen-containing groups existed on the catalysts surface are beneficial to improve the low-temperature catalytic activity. Additionally, compared with the Mn-CeOx(1:7)/AC@CNTs (n(Mn):n(Ce) =1:7) catalyst, the relative proportion of oxygen adsorbed surface and the amount of medium acid increased significantly on the Fe-Mn-CeOx(1:7)/AC@CNTs catalyst, making it have the good redox properties and surface acidity. The Fe-Mn-CeOx(1:7)/AC@CNTs catalyst shows the highest catalytic activity throughout the temperature window, with the NO conversion reaches >90% at 225～300 ℃, and the CB conversion >90% at 300 ℃. In addition, the NO conversion of Fe-Mn-CeOx(1:7)/AC@CNTs catalyst reaches 95% at 300℃ when CB is present.