Green rust (GR) is a potentially important compound for the reduction of heavy metal and organic pollutants in subsurface environment because of its high Fe(II) content, but many details of the actual reaction mechanism are lacking. The reductive capacity distribution within GR is a key to understand how and where the redox reaction occurs and computational chemistry can provide more details about the electronic properties of green rust. We constructed three sizes of cluster models of single layer GR (i.e., without interlayer molecules or ions) and calculated the charge distribution of these structures using density functional theory. We found that the Fe(II) and Fe(III) are distributed unevenly in the single layer GR. Within a certain range of Fe(II)/Fe(III) ratios, the outer iron atoms behave more like Fe(III) and the inner iron atoms behave more like Fe(II). These findings indicate that the interior of GR is more reductive than the outer parts and will provide new information to understand the GR redox interactions.

中文翻译：

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单层绿锈中 Fe(II)/Fe(III) 分布的密度泛函理论研究：聚类方法

绿锈病 (GR) 是一种潜在的重要化合物，可用于减少地下环境中的重金属和有机污染物，因为其 Fe(II) 含量高，但缺乏实际反应机理的许多细节。GR 中的还原容量分布是了解氧化还原反应如何发生以及发生在何处的关键，计算化学可以提供有关绿锈电子特性的更多详细信息。我们构建了三种尺寸的单层GR（即，没有夹层分子或离子）的簇模型，并使用密度泛函理论计算了这些结构的电荷分布。我们发现 Fe(II) 和 Fe(III) 在单层 GR 中分布不均匀。在一定的 Fe(II)/Fe(III) 比值范围内，外面的铁原子表现得更像 Fe(III)，里面的铁原子表现得更像 Fe(II)。这些发现表明，GR 的内部比外部更具还原性，将为理解 GR 氧化还原相互作用提供新信息。