Insight into the Effect of Oxygen Vacancy Concentration on the Catalytic Performance of MnO2
文献类型：期刊论文
| 作者 | Li, Li1; Feng, Xianghong1; Nie, Yao1; Chen, Siguo1; Shi, Feng1; Xiong, Kun1; Ding, Wei1; Qi, Xueqiang1; Hu, Jinsong2; Wei, Zidong1 |
| 刊名 | ACS CATALYSIS
 |
| 出版日期 | 2015-08-01 |
| 卷号 | 5期号:8页码:4825-4832 |
| 关键词 | oxygen vacancy oxygen reduction reaction DFT beta-MnO2 catalytic activity |
| 英文摘要 | Oxygen vacancies (OVs) are important for changing the geometric and electronic structures as well as the chemical properties of MnO2. In this study, we performed a DFT+U calculation on the electronic structure and catalytic performance of a P-MnO2 catalyst for the oxygen reduction reaction (ORR) with different numbers and extents of OVs. Comparing those results with the experimental XRD analysis, we determined that OVs produce a new crystalline phase of beta-MnO2. Changes in the electronic structure (Bader charges, band structure, partial density of states, local density of states, and frontier molecular orbital), proton insertion, and oxygen adsorption in beta-MnO2 (110) were investigated as a function of the bulk OVs. The results show that a moderate concentration of bulk OVs reduced the band gap, increased the Fermi and HOMO levels of the MnO2 (or MnOOH), and elongated the O-O bond of the adsorbed O-2 and coadsorbed O-2 with H. These changes substantially increase the conductivity of MnO2 for the catalysis of ORR However, an excessively high concentration of OVs in beta-MnO2 (110) will work against the catalytic enhancement of MnO2 for ORB. The DFT+U calculation reveals that a moderate concentration of OVs induced a large overlap of the surface Mn d(z2) orbitals, thus introducing an extra donor level at the bottom of the conductive band, which increased the conductivity of beta-MnO2 (110). Such a curvilinear change of the catalytic activity and electronic structure as a function of the oxygen vacancy concentration suggests that the beta-MnO2 with moderate concentration OVs exhibits the highest conductivity and catalytic activity for ORR. |
| 收录类别 | SCI |
| 语种 | 英语 |
| 公开日期 | 2015-10-27 |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/27720]  |
| 专题 | 化学研究所_分子纳米结构与纳米技术实验室 |
| 作者单位 | 1.Chongqing Univ, Coll Chem & Chem Engn, State Key Lab Power Transmiss Equipment & Syst Se, Chongqing 400044, Peoples R China 2.Chinese Acad Sci, Inst Chem, Key Lab Mol Nanostruct & Nanotechnol, Beijing 100190, Peoples R China |
| 推荐引用方式 GB/T 7714 | Li, Li,Feng, Xianghong,Nie, Yao,et al. Insight into the Effect of Oxygen Vacancy Concentration on the Catalytic Performance of MnO2[J]. ACS CATALYSIS,2015,5(8):4825-4832. |
| APA | Li, Li.,Feng, Xianghong.,Nie, Yao.,Chen, Siguo.,Shi, Feng.,...&Xia, Meirong.(2015).Insight into the Effect of Oxygen Vacancy Concentration on the Catalytic Performance of MnO2.ACS CATALYSIS,5(8),4825-4832. |
| MLA | Li, Li,et al."Insight into the Effect of Oxygen Vacancy Concentration on the Catalytic Performance of MnO2".ACS CATALYSIS 5.8(2015):4825-4832. |
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来源：化学研究所
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