The valence and site occupancy of substituting metals in magnetite spinel structure Fe3-xMxO4 (M = Cr, Mn, Co and Ni) and their influence on thermal stability: An XANES and TG-DSC investigation

被引：82

作者：

Liang, Xiaoliang ^{[1
,2
]}

Zhong, Yuanhong ^{[1
,2
]}

Zhu, Sanyuan ^{[1
]}

He, Hongping ^{[1
]}

Yuan, Peng ^{[1
]}

Zhu, Jianxi ^{[1
]}

Jiang, Zheng ^{[3
]}

机构：

[1] Chinese Acad Sci, Guangzhou Inst Geochem, Key Lab Mineral & Metallogeny, Guangzhou 510640, Guangdong, Peoples R China

[2] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

[3] Chinese Acad Sci, Shanghai Inst Appl Phys, SSRF, Shanghai 201800, Peoples R China

来源：

SOLID STATE SCIENCES | 2013年 / 15卷

基金：

中国国家自然科学基金;

关键词：

Magnetite; Substitution; XANES; Thermal stability; TG-DSC; ABSORPTION-SPECTRA; CATALYTIC-ACTIVITY; IRON-OXIDES; OXIDATION; FE; NICKEL; COBALT; MANGANESE; COPPER; DECOLORIZATION;

D O I：

10.1016/j.solidstatesciences.2012.10.005

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

Four series of substituted magnetite (Fe3-xMxO4, M = Cr, Mn, Co and Ni) were characterized by X-ray diffraction (XRD), X-ray absorption near-edge structure (XANES) spectroscopy, and thermogravimetry and differential thermal analysis (TG-DSC). XRD patterns confirmed the formation of samples with the spine! structure. XANES showed the valence and site occupancy of the substituting cations. Cr cations are in the valence of +3 and occupy the octahedral sites. The valences of Mn cation are +2 and +3. Mn2+ and Mn3+ cations preferentially entered the tetrahedral and octahedral sites, respectively. Both Co and Ni cations have a valence of +2 and mainly occupy the octahedral sites. The introduction of Cr and Ni cations obviously increases the amount of superficial hydroxyl groups. The incorporation of Mn, Co and Ni enhances the oxidation temperature of magnetite. All the four kinds of substituting cations in this study increase the temperature of phase transformation from maghemite (gamma-Fe2O3) to hematite (alpha-Fe2O3). The mechanism of substitution changing the temperatures of oxidation and phase transformation was also discussed. (C) 2012 Elsevier Masson SAS. All rights reserved.

引用

页码：115 / 122

页数：8

共 56 条

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