title: The variation of cationic microstructure in Mn-doped spinel ferrite during calcination and its effect on formaldehyde catalytic oxidation.
abstract: In this study, a series of Mn substituted spinel ferrites calcinated at different temperatures were used as catalysts for the oxidation of formaldehyde (HCHO). X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and H2 temperature-programmed reduction were conducted to characterize the structure and physico-chemical properties of catalysts, which were affected by calcination in the range of 200-600°C. Results show that all the ferrites were with spinel structure, and those calcinated in the range of 300-600°C were in the phase of maghemite. The calcination changed the valence and distribution of Mn and Fe on the ferrite surface, and accordingly the reducibility of ferrites. The HCHO catalytic oxidation test showed that with the increase of calcination temperature, the activity was initially improved until 400°C, but then decreased. The variation of HCHO conversion performance was well positively correlated to the variation of reduction temperature of surface Mn(4+) species. The remarkable effect of calcination on the catalytic activity of Mn-doped spinel ferrites for HCHO oxidation was discussed in view of reaction mechanism and variations in cationic microstructure of Mn-doped ferrites.
authors.affiliation: CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou 510640, PR China.
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Liang
authors.affiliation: CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou 510640, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.affiliation: CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou 510640, PR China. Electronic address: hehp@gig.ac.cn.
authors.forename: Hongping
authors.initials: H
authors.lastname: He
authors.affiliation: Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650, PR China.
authors.forename: Gaoling
authors.initials: G
authors.lastname: Wei
authors.affiliation: School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, PR China.
authors.forename: Tianhu
authors.initials: T
authors.lastname: Chen
authors.affiliation: CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou 510640, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Tan
authors.affiliation: CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou 510640, PR China.
authors.forename: Fuding
authors.initials: F
authors.lastname: Tan
authors.affiliation: CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou 510640, PR China.
authors.forename: Jianxi
authors.initials: J
authors.lastname: Zhu
authors.affiliation: CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou 510640, PR China.
authors.forename: Runliang
authors.initials: R
authors.lastname: Zhu
keywords: Calcination; Catalytic oxidation; Formaldehyde; Manganese substituted ferrite; Spinel