Insights into the Mechanism of Fe(II) Adsorption and Oxidation at Fe–Clay Mineral Surfaces from First-Principles Calculations
Insights into the Mechanism of Fe(II) Adsorption and Oxidation at Fe–Clay Mineral Surfaces from First-Principles Calculations
复制标题
DOI：
10.1021/jp4073125
复制
发表时间：
2013-10
影响因子：
3.7
通讯作者：
V. Alexandrov;K. Rosso
中科院分区：
文献类型：
--
作者：
V. Alexandrov;K. Rosso
含铁矿物表面氧化还原活性的界面反应性在许多环境过程中起着至关重要的作用，包括各种元素和污染物的地球化学循环。在这里，我们应用密度泛函理论（DFT）计算提供原子的洞察到水溶液中的Fe（II）和含铁粘土矿物囊脱石Fe 2Si 4 O 10（OH）2之间的非均相反应，通过研究其吸附机制和界面Fe（II）-Fe（III）的电子转移（ET）在边缘和基底表面。我们发现，在不同的表面位点（铁醇，硅烷醇，和混合）的边缘绑定的Fe（II）吸附复合物可能共存于（010）和（110）的边缘小平面，与复合物在铁醇FeO（H）网站是最积极有利的，并耦合到质子转移。ET活化能的计算表明，界面ET到二八面体Fe（III）片是可能的粘土边缘，发生主要是但不完全通过络合物吸附在ferrinol网站和migg…
Interfacial reactivity of redox-active iron-bearing mineral surfaces plays a crucial role in many environmental processes including biogeochemical cycling of various elements and contaminants. Herein, we apply density functional theory (DFT) calculations to provide atomistic insights into the heterogeneous reaction between aqueous Fe(II) and the Fe-bearing clay mineral nontronite Fe2Si4O10(OH)2 by studying its adsorption mechanism and interfacial Fe(II)–Fe(III) electron transfer (ET) at edge and basal surfaces. We find that edge-bound Fe(II) adsorption complexes at different surface sites (ferrinol, silanol, and mixed) may coexist on both (010) and (110) edge facets, with complexes at ferrinol FeO(H) sites being the most energetically favorable and coupled to proton transfer. Calculation of the ET activation energy suggests that interfacial ET into dioctahedral Fe(III) sheets is probable at the clay edges and occurs predominantly but not exclusively through the complexes adsorbed at ferrinol sites and mig...