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论文类型：期刊论文

发表时间：2020-06-05

发表刊物：JOURNAL OF HAZARDOUS MATERIALS

收录刊物：PubMed、EI、SCIE

卷号：391

页面范围：122181

ISSN号：0304-3894

关键字：Oxygen vacancy; Toluene oxidation; Two-dimensional MnO2; Cu doping; In situ DRIFTS

摘要：Oxygen vacancy acts an important role in adjusting the chemical properties of MnO2. In this paper, two-dimensional MnO2 catalysts with different oxygen vacancy concentration are obtained by doping Cu2+. It is researched that the K+ species in the interlayer of birnessite-type MnO2 can be substituted during the Cu2+ doping process. Meanwhile, this process will generate the oxygen vacancy. Interestingly, the formation of an appropriate numbers of oxygen vacancy in MnO2 distinctly enhances the low-temperature reducibility and oxygen species activity, which improves the catalytic activity for the toluene oxidation (T-100 = 220 degrees C, E-a= 43.6 kJ/ mol). However, an excessive concentration of oxygen vacancy in MnO2 sample performs against the activity improvement for toluene oxidation. In situ DRIFTS are applied to elucidate the main intermediates and conversion pathway on MnO2-OV3 with moderate concentration of oxygen vacancy. The results demonstrate that the adsorbed toluene can interact with oxygen species of catalyst to form physisorbed benzaldehyde, aldehydic adsorbate and benzoate species. In addition, it is found that the oxygen vacancy concentration plays an important effect on the oxidation of benzoate species owing to the acceleration effect of oxygen vacancy in the activation of gaseous oxygen.