Geometric and electronic modification of the active Fe3+ sites of α-Fe2O3 for highly efficient toluene combustion.
Geometric and electronic modification of the active Fe3+ sites of α-Fe2O3 for highly efficient toluene combustion.
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DOI：
10.1016/j.jhazmat.2020.123233
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发表时间：
2020-06
影响因子：
13.6
通讯作者：
Yi Liu;Tianhua Zhang;Shusheng Li;Kai Zhang;Xiuyun Wang;Y. Zhan;Ying Zheng;Lilong Jiang
中科院分区：
文献类型：
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作者：
Yi Liu;Tianhua Zhang;Shusheng Li;Kai Zhang;Xiuyun Wang;Y. Zhan;Ying Zheng;Lilong Jiang
In the present study, catalytically inactive or low-active Ti4+(d0) or Zn2+(d10) ions were doped to α-Fe2O3to tune the geometric and electronic engineering for Fe active center. X-ray absorption near edge structure (XANES) and Powder X-ray diffraction (XRD) analyses coupled with density functional theory (DFT) calculation show that the added of Ti4+could occupy the interstitial octahedral or tetrahedral sites, resulting in surface Fe2+species are oxidized to octahedrally coordinated Fe3+. As a result, more oxygen vacancies are generated, which improve the catalytic performance for toluene combustion. On the other hand, Fe2+was substituted by Zn2+ion could result in the partial destruction of hematite crystal structure, forming an additional phase of ZnFe2O4, and meanwhile part of Zn2+ions replace the octahedrally coordinated Fe3+sites, and therefore significantly decreasing the toluene catalytic performance. Moreover, our studies demonstrate that the combustions of toluene over Fe-based catalysts involve both the MvK and L-H mechanisms.
