title: Selenium catalyzed Fe(III)-EDTA reduction by Na2SO3: a reaction-controlled phase transfer catalysis.
abstract: Fe(II)-EDTA, a typical chelated iron, is able to coordinate with nitric oxide (NO) which accelerates the rates and kinetics of the absorption of flue gas. However, Fe(II)-EDTA can be easily oxidized to Fe(III)-EDTA which is unable to absorb NO. Therefore, the regeneration of fresh Fe(II)-EDTA, which actually is the reduction of Fe(III)-EDTA to Fe(II)-EDTA, becomes a crucial step in the denitrification process. To enhance the reduction rate of Fe(III)-EDTA, selenium was introduced into the SO3 (2-)/Fe(III)-EDTA system as catalyst for the first time. By comparison, the reduction rate was enhanced by four times after adding selenium even at room temperature (25 °C). Encouragingly, elemental Se could precipitate out when SO3 (2-) was consumed up by oxidation to achieve self-separation. A catalysis mechanism was proposed with the aid of ultraviolet-visible (UV-Vis) spectroscopy, Tyndall scattering, horizontal attenuated total reflection Fourier transform infrared (HATR-FTIR) spectroscopy, and X-ray diffraction (XRD). In the catalysis process, the interconversion between SeSO3 (2-) and nascent Se formed a catalysis circle for Fe(III)-EDTA reduction in SO3 (2-) circumstance.
authors.affiliation: School of Metallurgy and Environment, Central South University, Changsha, 410083, China.
authors.forename: Kaisong
authors.initials: K
authors.lastname: Xiang
authors.affiliation: School of Metallurgy and Environment, Central South University, Changsha, 410083, China. leolau@csu.edu.cn.|Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China. leolau@csu.edu.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.affiliation: School of Metallurgy and Environment, Central South University, Changsha, 410083, China.
authors.forename: Bentao
authors.initials: B
authors.lastname: Yang
authors.affiliation: School of Metallurgy and Environment, Central South University, Changsha, 410083, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Zhang
authors.affiliation: School of Metallurgy and Environment, Central South University, Changsha, 410083, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Yang
authors.affiliation: School of Metallurgy and Environment, Central South University, Changsha, 410083, China.
authors.forename: Zhilou
authors.initials: Z
authors.lastname: Liu
authors.affiliation: School of Metallurgy and Environment, Central South University, Changsha, 410083, China.
authors.forename: Cao
authors.initials: C
authors.lastname: Liu
authors.affiliation: School of Metallurgy and Environment, Central South University, Changsha, 410083, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Xie
authors.affiliation: School of Metallurgy and Environment, Central South University, Changsha, 410083, China.|Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Chai
authors.affiliation: School of Metallurgy and Environment, Central South University, Changsha, 410083, China. mxbcsu@163.com.|Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China. mxbcsu@163.com.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Min
mesh_terms: D002384:Catalysis; D058440:Denitrification; D004492:Edetic Acid / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry*; D007700:Kinetics; D009569:Nitric Oxide / Q000737:chemistry; D010084:Oxidation-Reduction; D012643:Selenium / Q000737:chemistry*; D013447:Sulfites / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D005296:Ferrous Compounds; D013447:Sulfites; C055526:Fe(II)-EDTA; D009569:Nitric Oxide; D004492:Edetic Acid; D012643:Selenium; C025026:sodium sulfite
keywords: Catalysis; Desulfurization and denitrification; Fe(III)-EDTA reduction; Reaction-controlled phase transfer; Selenium