Proton Traffic Jam: Effect of Nanoconfinement and Acid Concentration on Proton Hopping Mechanism.
Proton Traffic Jam: Effect of Nanoconfinement and Acid Concentration on Proton Hopping Mechanism.
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DOI：
10.1002/anie.202108766
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发表时间：
2021-11-22
影响因子：
16.6
通讯作者：
Head-Gordon, Teresa
中科院分区：
文献类型：
--
作者：
Adams, Ellen M.;Hao, Hongxia;Leven, Itai;Ruettermann, Maximilian;Wirtz, Hanna;Havenith, Martina;Head-Gordon, Teresa
利用太赫兹吸收、介电弛豫光谱和反应性力场模拟等方法研究了纳米级反离子束中浓HCl酸池中水网络的性质。我们发现，只有在临界胶束尺寸W0=9时，溶剂化质子配合物才会在水池中形成，并伴随着Grotthuss向前穿梭机制的变化，从而有利于局部振荡跳变。这是由于H+和Cl−离子更倾向于吸附到胶束界面上，再加上酸浓度效应，导致“交通堵塞”，在这种情况下，即使胶束尺寸增加，水合氢离子的氢键基序的短路也会降低整个水内部的正向跳跃速率。这些发现对大气化学、生物化学和生物物理环境以及能源材料具有重要意义，因为对这些过程至关重要的质子的传输可能由于限制、聚集和/或浓度而受到抑制。质子在非离子反胶束内的输运机制取决于质子浓度（[H+]）和纳米限制环境的大小。对于小的反向胶束和/或低[H+]，质子通过Grotthuss机制（正向跳跃）扩散。在较大的反胶束和/或高[H+]时，离子在反胶束界面积聚，导致质子“交通堵塞”，其中振荡跳跃机制成为主导。
The properties of the water network in concentrated HCl acid pools in nanometer‐sized reverse nonionic micelles were probed with TeraHertz absorption, dielectric relaxation spectroscopy, and reactive force field simulations capable of describing proton hopping mechanisms. We identify that only at a critical micelle size of W0=9 do solvated proton complexes form in the water pool, accompanied by a change in mechanism from Grotthuss forward shuttling to one that favors local oscillatory hopping. This is due to a preference for H+ and Cl− ions to adsorb to the micelle interface, together with an acid concentration effect that causes a “traffic jam” in which the short‐circuiting of the hydrogen‐bonding motif of the hydronium ion decreases the forward hopping rate throughout the water interior even as the micelle size increases. These findings have implications for atmospheric chemistry, biochemical and biophysical environments, and energy materials, as transport of protons vital to these processes can be suppressed due to confinement, aggregation, and/or concentration. The mechanism of proton transport within nonionic reverse micelles is dependent on the proton concentration ([H+]) and the size of the nanoconfined environment. For small reverse micelles and/or low [H+], protons diffuse via the Grotthuss mechanism (forward hopping). In larger reverse micelles and/or at high [H+], ions accumulate at the reverse micelles interface, resulting in a proton “traffic jam,” in which an oscillatory hopping mechanism becomes dominant.
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影响因子：
16.6
作者：
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通讯作者：
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