A DFT-Based Model on the Adsorption Behavior of H2O, H+, Cl-, and OH- on Clean and Cr-Doped Fe(110) Planes
A DFT-Based Model on the Adsorption Behavior of H2O, H+, Cl-, and OH- on Clean and Cr-Doped Fe(110) Planes
复制标题
基于 DFT 的 H2O、H、Cl 和 OH 在清洁和 Cr 掺杂 Fe(110) 平面上吸附行为的模型
DOI：
10.3390/coatings8020051
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发表时间：
2018-02-01
期刊：
影响因子：
3.4
通讯作者：
Zheng, Shunli
中科院分区：
文献类型：
--
作者：
Hu, Jun;Wang, Chaoming;Zheng, Shunli
采用基于密度泛函理论（DFT）的模型，研究了四种典型吸附剂（H2O、H+、Cl-和OH-）对Fe（110）、Cr（110）和Cr掺杂Fe（110）三个不同平面的影响。通过上述四种吸附剂的吸附机理验证，掺杂cr的Fe（110）平面是三种吸附体中最稳定的面。通过吸附能和电子结构证实，Cr掺杂会大大增强邻近Fe原子的给电子能力，从而促进带正电的H+的吸附。同时，Cr对带负电荷的吸附物（如H2O的Cl-、O、OH-）的亲和力由于其电子供体能力的减弱而提高。另一方面，表面原子与吸附剂之间的强键也会削弱金属原子之间的键，从而导致结构变形和电荷在天然晶体结构中重新分布。这样，晶体就更容易受到腐蚀。
The impact of four typical adsorbates, namely H2O, H+, Cl-, and OH-, on three different planes, namely, Fe(110), Cr(110) and Cr-doped Fe(110), was investigated by using a density functional theory (DFT)-based model. It is verified by the adsorption mechanism of the abovementioned four adsorbates that the Cr-doped Fe(110) plane is the most stable facet out of the three. As confirmed by the adsorption energy and electronic structure, Cr doping will greatly enhance the electron donor ability of neighboring Fe atoms, which in turn prompts the adsorption of the positively charged H+. Meanwhile, the affinity of Cr to negatively charged adsorbates (e.g., Cl- and O of H2O, OH-) is improved due to the weakening of its electron donor ability. On the other hand, the strong bond between surface atoms and the adsorbates can also weaken the bond between metal atoms, which results in a structure deformation and charge redistribution among the native crystal structure. In this way, the crystal becomes more vulnerable to corrosion.