Proton Conductivity in Hydrogen Phosphate/Sulfates from a Coupled Molecular Dynamics/Lattice Monte Carlo (cMD/LMC) Approach
Proton Conductivity in Hydrogen Phosphate/Sulfates from a Coupled Molecular Dynamics/Lattice Monte Carlo (cMD/LMC) Approach
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DOI：
10.1021/acs.jpcc.6b05822
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发表时间：
2016-09
影响因子：
3.7
通讯作者：
C. Dreßler;G. Kabbe;D. Sebastiani
中科院分区：
文献类型：
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作者：
C. Dreßler;G. Kabbe;D. Sebastiani
CsHnXO_4型固体酸（X = P，S; n = 2，1）的离子电导率随化学取代P的参与和晶体结构的不同而变化（CsH_2 PO_4的Tc = 503 K）。我们应用最近开发的耦合分子动力学/晶格Monte Carlo模拟方法（cMD/LMC 1，2）来解释磷酸盐/硫酸盐和温度/相位相关的质子电导率在分子水平上的变化。我们的模拟方法阐明了相对重要性的两个关键组成部分的Grotthuss型质子传导机制，质子跳跃和结构重定向，作为一个功能的化学/化学条件。我们发现，化学取代导致的质子跳跃率的实质性变化，但结果只有在一个温和的变化的质子扩散率。CsH_2PO_4的温度变化导致阴离子旋转频率的显著响应，这是质子传导的限速过程。在parti.
The ionic conductivity of solid acids of CsHnXO4 type (X = P, S; n = 2, 1) varies upon chemical substitution P ↔ S and between different crystal structures (Tc = 503 K for CsH2PO4). We apply a recently developed coupled molecular dynamics/lattice Monte Carlo simulation approach (cMD/LMC1,2) to explain both the phosphate/sulfate and temperature/phase-related variations of the proton conductivity on a molecular level. Our simulation method elucidates the relative importance of the two key components of the Grotthuss-type proton conduction mechanism, proton hopping and structural reorientation, as a function of the chemical/thermodynamical conditions. We find that the chemical substitution leads to a substantial change in the proton hopping rate, which however results only in a modest variation of the proton diffusivity. The variation of the temperature of CsH2PO4 results in a significant response of the anion rotation frequency, which turns out to be the rate-limiting process for proton conduction. In parti...