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.
Institute of Chemistry for Health and Life Sciences, Chimie ParisTech, PSL Research University, CNRS, F-75005 Paris, France.
Environ Int. 2022 Dec;170:107619. doi: 10.1016/j.envint.2022.107619. Epub 2022 Nov 4.
In this work, S doped FeB (FeB-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) of 0.956 h by 10.0at% S doped FeB (corresponding to FeB-S), compared to D and k values 37.3% and 0.067 h by FeB, respectively. The major dechlorination products of acetylene, ethene, ethane and C-C hydrocarbon compounds were observed from a reductive β-elimination pathway. S doped and undoped FeB 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 FeB and guides the potential design of zero-valent iron (ZVI) with properties tailored for chlorinated hydrocarbons dechlorination.
在这项工作中，通过烧结法合成了 S 掺杂的 FeB（FeB-S），并将其应用于增强三氯乙烯（TCE）的脱氯。与 FeB 的降解率（D）为 37.3%和反应速率常数（k）为 0.067 h 相比，10.0at% S 掺杂的 FeB（对应于 FeB-S）的 TCE 的降解率（D）为 99.8%，反应速率常数（k）为 0.956 h。从还原β消除途径观察到了乙炔、乙烯、乙烷和 C-C 烃类化合物等主要脱氯产物。S 掺杂和未掺杂的 FeB 可以形成一级原位原电池，而返回的 S 提供了二级原电池，以进一步增强电子转移。通过密度泛函理论（DFT）计算验证了掺杂 S 作为电子供体增加了局部未配对电子的密度，而富电子的 Fe 原子导致更强的还原性。这项工作提供了对 S 掺杂 FeB 增强机制的全面了解，并为针对氯化烃脱氯特性的零价铁（ZVI）的潜在设计提供了指导。
