Abstract:
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.
摘要:
绿锈(GR)由于其高Fe(II)含量,是地下环境中还原重金属和有机污染物的潜在重要化合物,但是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发生的方式和位置的关键,计算化学可以提供有关绿锈电子特性的更多详细信息。我们构建了三种大小的单层GR聚类模型(即,没有层间分子或离子),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。Fe(II)/Fe(III)比值在一定范围内,外部铁原子的行为更像Fe(III),内部铁原子的行为更像Fe(II)。这些发现表明,GR的内部比外部更具还原性,并将为理解GR的氧化还原相互作用提供新的信息。