期刊
SMALL
卷 17, 期 43, 页码 -出版社
WILEY-V C H VERLAG GMBH
DOI: 10.1002/smll.202102408
关键词
low-temperature catalysis; NH3-SCR; oxygen defects; phase transformation; beta-MnO2
类别
资金
- National Natural Science Foundation of China [21576054, 61935017]
- Science and Technology Planning Project of Guangdong Province [2016B020241003]
- Natural Science Foundation of Guangdong Province [2018A030310563, 2019A1515012186]
- Science and Technology Development Fund, Macao SAR [FDCT-0044/2020/A1, FDCT-091/2017/A2, FDCT-014/2017/AMJ]
- UM's research fund [MYRG2018-00148-IAPME]
- Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials [2019B121205002]
The authors obtained oxygen defect-rich beta-MnO2 through a crystal phase transformation process, which showed high efficiency in low-temperature selective catalytic reduction of NO with NH3. The introduction of oxygen defects enhances the adsorption properties for reactants and decreases the energy barriers of NH2 formation, contributing to the high efficiency of low-temperature SCR activity.
The catalysts for low-temperature selective catalytic reduction of NO with NH3 (NH3-SCR) are highly desired due to the large demand in industrial furnaces. The characteristic of low-temperature requires the catalyst with rich active sites especially the redox sites. Herein, the authors obtain oxygen defect-rich beta-MnO2 from a crystal phase transformation process during air calcination, by which the as-prepared gamma-MnO2 nanosheet and nanorod can be conformally transformed into the corresponding beta-MnO2. Simultaneously, this transformation accompanies oxygen defects modulation resulted from lattice rearrangement. The most active beta-MnO2 nanosheet with plentiful oxygen defects shows a high efficiency of > 90% NO conversion in an extremely wide operation window of approximate to 120-350 degrees C. The detailed characterizations and density functional theory (DFT) calculations reveal that the introduction of oxygen defects enhances the adsorption properties for reactants and decreases the energy barriers of *NH2 formation more than 0.3 eV (approximate to 0.32-0.37 eV), which contributes to a high efficiency of low-temperature SCR activity. The authors finding provides a feasible approach to achieve the oxygen defect engineering and gains insight into manganese-based catalysts for low-temperature NO removal or pre-oxidation.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据