论文标题
使用量子连续近似值的氯化离子插入Al/al $ _2 $ $ _3 $接口将氯化离子插入到al/al/al $ _2
Voltage-dependent first-principles simulation of insertion of chloride ions into Al/Al$_2$O$_3$ interfaces using the Quantum Continuum Approximation
论文作者
论文摘要
实验表明，相对于标准的氢电极（SHA），在电势$> -0.5 $ V的铝表面上可以发展点腐蚀。直到最近，由于难以将电压纳入密度功能理论（DFT）计算，因此还没有在原子尺度上进行严格探索铝的点腐蚀发作。我们介绍了量子连续近似（QCA），这些量子近似（QCA）是对金属绝缘体和绝缘体 - 溶剂接口的明确dft计算，以连续泊松托管玻尔兹曼静电分布，描述了绝缘区域的大部分。通过减少用DFT通过数量级明确模拟的原子数量，QCA使第一原理对现实电化学接口的电压的预测可行。在开发了此技术之后，我们将QCA应用于AL（111）/$α$ -AL $ _2 $ o $ $ _3 $（0001）接口的氧气空位的氯化原子的形成能，作为应用伏特的功能。我们预测，氯化物插入只有在Al $ _2 $ o $ o $ _3 $的晶界系统中有利，电压$> -0.2 $ v（she）。我们的结果大致与实验证明的腐蚀发作大致相符，这表明QCA以合理的计算成本对现实的电化学系统进行建模。
Experiments have shown that pitting corrosion can develop in aluminum surfaces at potentials $> -0.5$ V relative to the standard hydrogen electrode (SHE). Until recently, the onset of pitting corrosion in aluminum has not been rigorously explored at an atomistic scale because of the difficulty of incorporating a voltage into density functional theory (DFT) calculations. We introduce the Quantum Continuum Approximation (QCA) which self-consistently couples explicit DFT calculations of the metal-insulator and insulator-solution interfaces to continuum Poisson-Boltzmann electrostatic distributions describing the bulk of the insulating region. By decreasing the number of atoms necessary to explicitly simulate with DFT by an order of magnitude, QCA makes the first-principles prediction of the voltage of realistic electrochemical interfaces feasible. After developing this technique, we apply QCA to predict the formation energy of chloride atoms inserting into oxygen vacancies in Al(111)/$α$-Al$_2$O$_3$ (0001) interfaces as a function of applied voltage. We predict that chloride insertion is only favorable in systems with a grain boundary in the Al$_2$O$_3$ for voltages $> -0.2$ V (SHE). Our results roughly agree with the experimentally demonstrated onset of corrosion, demonstrating QCA's utility in modeling realistic electrochemical systems at reasonable computational cost.
