NO oxidation activity of Ag-doped perovskite catalysts
NO oxidation activity of Ag-doped perovskite catalysts
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DOI：
10.1016/j.jcat.2014.09.007
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发表时间：
2014-11
影响因子：
7.3
通讯作者：
D. Yoon;Eunho Lim;Young-Jin Kim;Ji Ho Kim;Taekyung Ryu;Sumin Lee;B. Cho;I. Nam;J. Choung
中科院分区：
文献类型：
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作者：
D. Yoon;Eunho Lim;Young-Jin Kim;Ji Ho Kim;Taekyung Ryu;Sumin Lee;B. Cho;I. Nam;J. Choung
研究了柠檬酸法制备的掺银钙钛矿催化剂La1−xAgxMnO3对NO的催化氧化作用。与LaMnO3相比，La1−xagxmno3表现出更强的NO氧化活性，其最大活性atx= 0.2，证实了la0.8 ag0.2 mno3作为最有前途的NO氧化催化剂之一的潜力。通过XRD、SEM、XPS、O2- tpd、H2-TPR、(NO + O2)-TPRD和DRIFT研究发现，la0.8 ag0.2 mno3具有较高的反应活性主要是由于LaMnO3中Ag+部分取代La3+而在其表面产生了较高的氧空位浓度。在钙钛矿氧空位上形成的单齿和双齿硝酸盐似乎是在掺银钙钛矿催化剂上进行NO氧化反应的主要反应中间体。基于氧空位、氧、NO、no2和NO3的氧化还原过程，提出了La1−xagxmno3上NO氧化的合理反应途径。
Ag-doped perovskite catalysts (La1−xAgxMnO3) prepared by the citric acid method were investigated for the catalytic oxidation of NO. Compared to LaMnO3, La1−xAgxMnO3revealed a superior NO oxidation activity with its maximum activity atx= 0.2, confirming the potential of La0.8Ag0.2MnO3as one of the most promising NO oxidation catalysts. The high reactivity of La0.8Ag0.2MnO3is mainly due to the high oxygen vacancy concentration on its surface produced by the partial substitution of La3+with Ag+in LaMnO3, as determined by the XRD, SEM, XPS, O2-TPD, H2-TPR, (NO + O2)-TPRD and DRIFT studies. The mono- and bi-dentate nitrates formed on the oxygen vacancies of perovskite appear to be the primary reaction intermediates for the NO oxidation reaction over the Ag-doped perovskite catalyst. A plausible reaction pathway of the NO oxidation over La1−xAgxMnO3has been postulated on the basis of the redox process involving the oxygen vacancy, oxygen, NO, NO2and NO3.