Electron induced efficient dechlorination of trichlorethylene with S doped Fe2B: The enhancement mechanism of S

Yuelin Xie; Qinfan Wang; Zihan Guo; Linbo Qian; Mengfang Chen; Jingchun Yan

doi:10.1016/j.envint.2022.107619

Electron induced efficient dechlorination of trichlorethylene with S doped Fe₂B: The enhancement mechanism of S

Environ Int. 2022 Dec:170:107619. doi: 10.1016/j.envint.2022.107619. Epub 2022 Nov 4.

Authors

Yuelin Xie¹, Qinfan Wang², Zihan Guo³, Linbo Qian³, Mengfang Chen³, Jingchun Yan⁴

Affiliations

¹ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Laboratoire de Réactivité de Surface (LRS), Sorbonne Université, CNRS, 4 Place Jussieu, F-75005 Paris, France.
² Institute of Chemistry for Health and Life Sciences, Chimie ParisTech, PSL Research University, CNRS, F-75005 Paris, France.
³ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: jcyan@issas.ac.cn.

PMID: 36379201
DOI: 10.1016/j.envint.2022.107619

Abstract

In this work, S doped Fe₂B (Fe₂B-S) was synthesized by sintering method and applied for the enhanced dechlorination of trichlorethylene (TCE). The degradation ratio (D) of TCE was 99.8% with reaction rate constant (k_obs) of 0.956 h^-1 by 10.0at% S doped Fe₂B (corresponding to Fe₂B-S_10.0), compared to D and k_obs values 37.3% and 0.067 h^-1 by Fe₂B, respectively. The major dechlorination products of acetylene, ethene, ethane and C₃-C₆ hydrocarbon compounds were observed from a reductive β-elimination pathway. S doped and undoped Fe₂B could form the first-level in-situ galvanic cell, and the returned S provided a second-level galvanic cell to further enhance electron transfer. The doped S worked as electron donor to increase the density of localized unpaired electrons, and the electron enriched Fe atoms leading to stronger reducibility were verified by the density functional theory (DFT) calculation. This work provides a complete insight into the enhancement mechanism of S doped Fe₂B and guides the potential design of zero-valent iron (ZVI) with properties tailored for chlorinated hydrocarbons dechlorination.

Keywords: Dechlorination; Fe(2)B; S; Trichlorethylene.