分别在以P123为软模板和无P123的条件下制备8个钙钛矿型催化剂La1xSrxCo1-yCuyO3(x=0,0.1;y=0,0.2),用x射线衍射(XRD)、扫描电镜(SEM)、X射线能谱仪(EDS)、BET和X射线光电子能谱(XPS)进行了表征,并测试了它们对CO+ NO反应的催化活性.结果表明,以P123为软模板制备的催化剂具有更多大孔径段的介孔和小孔径段的大孔,更大的孔容,更多的氧空位,同时表面La的偏析更少,表面Co的含量以及Co3+/Co2+比例更高.因而,催化剂的催化活性明显优于无模板法制备的催化剂,其中对NO转化率的提升尤为显著.Sr对La的适量取代可以促进CO的氧化反应,而Cu掺杂会降低CO和NO的转化率.
Eight perovskite-type catalysts La1-xSrxCo1-yCuyO3 (x =0,0.1;y =0,0.2) were prepared under the conditions with and without P123 as soft template respectively.They were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),energy dispersive spectrometry (EDS),Brunauer-emmett-teller (BET) and X-ray photoelectron spectroscopy (XPS).In addition,the catalytic activity for CO + NO was tested.The results indicated that the P123-templated samples had more large mesopores,small macropores and oxygen vacancies,larger pore volume,reduced surface La segregation,increased content of surface Co and ratio of Co3+/Co2+ in comparison with the template-free ones.Therefore,the catalytic activity of P123-templated samples is better than that of the template-free ones obviously,especially for NO.An appropriate amount of Sr substitution for La promotes the oxidation of CO,whereas copper-doping reduces the catalytic activity for CO + NO.
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