Mn(II) 加速吡啶甲酸辅助 Fenton 反应：对锰在均相 Fenton AOP 中作用的新见解,Environmental Science & Technology

当前位置： X-MOL 学术 › Environ. Sci. Technol. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Mn(II) 加速吡啶甲酸辅助 Fenton 反应：对锰在均相 Fenton AOP 中作用的新见解
Environmental Science & Technology ( IF 10.8 ) Pub Date : 2022-05-03 , DOI: 10.1021/acs.est.1c08796
Zhichao Yang _{1,

2} , Chao Shan _{1,

3} , Joseph J Pignatello ₂ , Bingcai Pan _{1,

3}

Affiliation

均相 Fe 催化的 Fenton 反应仍然是一种有吸引力的废水处理高级氧化工艺，但在方便的 pH 值下维持 Fe(III)/Fe(II) 氧化还原循环而不需要昂贵的能量或还原剂输入仍然是一个挑战。众所周知，Mn(II) 会加速 Fenton 反应，但该机制从未被确定。我们报告了在 pH 4.5-6.0 下，吡啶甲酸 (PICA) 辅助 Fenton 反应对 Mn(II) 加速阿特拉津或 2,4,6-三氯苯酚降解的系统动力学和光谱研究。Mn(II) 加速Fe(III) 的还原、超氧自由基(HO ₂^• /O ₂^•– ) 的形成和羟基自由基(HO ^• ) 的形成。A Mn(II/III)-H ₂ O正如文献中提出的那样，作为活性氧的独立来源的_{2氧化还原循环被证明是微不足道的。}相反，Mn(II) 通过直接和催化参与 Fe(III)/Fe(II) 氧化还原循环来提供帮助。最初，Mn(II)（作为 Mn ^II (PICA) ⁺）与氢过氧铁物种 PICA-Fe ^III -OOH 络合。生成的双核配合物经过分子内电子转移得到 Fe(II)，随后由 H ₂ O _{2生成 HO}^•以及随后分解为 HO ₂^• /O ₂^•–的MnO ₂⁺（Fe（III）还原剂）和Mn（II），完成催化循环。^{该方案可能适用于通过 Fe III} -OOH 中间体的其他 Fenton 型系统。这里的研究结果将为使用 Mn(II) 和螯合剂的实用且可持续的 Fenton 基 AOP 的设计提供信息。

"点击查看英文标题和摘要"

Mn(II) Acceleration of the Picolinic Acid-Assisted Fenton Reaction: New Insight into the Role of Manganese in Homogeneous Fenton AOPs

The homogeneous Fe-catalyzed Fenton reaction remains an attractive advanced oxidation process for wastewater treatment, but sustaining the Fe(III)/Fe(II) redox cycle at a convenient pH without the costly input of energy or reductants remains a challenge. Mn(II) is known to accelerate the Fenton reaction, yet the mechanism has never been confidently established. We report a systematic kinetic and spectroscopic investigation into Mn(II) acceleration of atrazine or 2,4,6-trichlorophenol degradation by the picolinic acid (PICA)-assisted Fenton reaction at pH 4.5–6.0. Mn(II) accelerates Fe(III) reduction, superoxide radical (HO₂^•/O₂^•–) formation, and hydroxyl radical (HO^•) formation. A Mn(II/III)-H₂O₂ redox cycle as an independent source of reactive oxygen species, as proposed in the literature, is shown to be insignificant. Rather, Mn(II) assists by participating directly and catalytically in the Fe(III)/Fe(II) redox cycle. Initially, Mn(II) (as Mn^II(PICA)⁺) complexes with a ferric hydroperoxo species, PICA-Fe^III-OOH. The resulting binuclear complex undergoes intramolecular electron transfer to give Fe(II), which later generates HO^• from H₂O₂, plus MnO₂⁺, which later decomposes to HO₂^•/O₂^•– (an Fe(III) reductant) and Mn(II), completing the catalytic cycle. This scheme may apply to other Fenton-type systems that go through an Fe^III-OOH intermediate. The findings here will inform the design of practical and sustainable Fenton-based AOPs employing Mn(II) in combination with chelating agents.

更新日期：2022-05-03

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南