Formation of environmentally persistent free radicals on molecular sieves: The role of Lewis acid sites

IF 6.1 2区环境科学与生态学 Q1 ENVIRONMENTAL SCIENCES

Ecotoxicology and Environmental Safety Pub Date : 2025-09-25 DOI:10.1016/j.ecoenv.2025.119121

Hao Li, Wenjun Duan, Hao Jiang, Manling Zhang, Di Lang, Wei Du, Zhaofeng Chang, Peng Zhang, Bo Pan

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引用次数: 0

Abstract

Environmental persistent free radicals (EPFRs) generated on metal oxide surfaces have garnered significant research interest due to their environmental persistence and biological toxicity. While the catalytic role of Lewis acid sites (LAS) in EPFR formation has been hypothesized, the specific mechanisms underlying LAS-mediated generation at ambient temperature remain poorly understood. This investigation systematically elucidates the critical role of LAS concentration in molecular sieves for EPFR formation through polycyclic aromatic hydrocarbons (PAHs) adsorption under ambient conditions. Our results demonstrate that EPFR generation efficiency follows a distinct hierarchy among ultra-stable Y-type (USY) molecular sieves: USY(5.4) > USY(11) > USY(8), showing a strong positive correlation (p < 0.05) with LAS concentration. The absence of detectable EPFR signals on silica controls confirms LAS as essential active sites for radical stabilization. The concentration of EPFRs generated by different PAHs on the molecular sieve follows the order of pyrene (PYR) > anthracene (ANT) > phenanthrene (PHE) > naphthalene (NAP), which was negatively correlated (p < 0.05) with the ionization potential (IP) of PAHs. This indicates that the electron transfer ability of PAH also affects the generation of EPFRs. In addition, the acute toxicity of EPFRs was evaluated using Photobacterium phosphoreum T3 (PPT₃), and the inhibition rate of the luminescent bacteria was positively correlated with concentration of EPFRs and the mediated generation of ROS. The results of this study can contribute to the understanding of the generation mechanism and environmental risks of EPFRs.

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环境持久性自由基在分子筛上的形成：路易斯酸位点的作用

在金属氧化物表面产生的环境持久性自由基（Environmental persistent free radicals, EPFRs）由于其环境持久性和生物毒性而引起了广泛的研究兴趣。虽然Lewis酸位点（LAS）在EPFR形成中的催化作用已经被假设，但在环境温度下LAS介导的生成的具体机制仍然知之甚少。本研究系统地阐明了LAS浓度在环境条件下通过多环芳烃（PAHs）吸附形成EPFR的关键作用。我们的研究结果表明，在超稳定y型（USY）分子筛中，EPFR的生成效率具有明显的等级关系：USY(5.4) >； USY(11) >； USY(8)，与LAS浓度呈强正相关（p <； 0.05）。二氧化硅控制中没有可检测到的EPFR信号，这证实了LAS是自由基稳定的重要活性位点。不同多环芳烃在分子筛上生成EPFRs的浓度顺序为芘（PYR） >； 蒽（ANT） >； 菲（PHE） >； 萘（NAP），与多环芳烃的电离势（IP）呈负相关（p <； 0.05）。这表明多环芳烃的电子传递能力也影响epfr的产生。此外，利用光细菌磷T3 （PPT3）评价EPFRs的急性毒性，发光细菌的抑制率与EPFRs浓度和介导的ROS生成呈正相关。本研究结果有助于理解epfr的产生机制和环境风险。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Ecotoxicology and Environmental Safety 环境科学-毒理学

CiteScore

12.10

自引率

5.90%

发文量

1234

审稿时长

88 days

期刊介绍： Ecotoxicology and Environmental Safety is a multi-disciplinary journal that focuses on understanding the exposure and effects of environmental contamination on organisms including human health. The scope of the journal covers three main themes. The topics within these themes, indicated below, include (but are not limited to) the following: Ecotoxicology、Environmental Chemistry、Environmental Safety etc.