Increasing the Alkaline Stability of N,N-Diaryl Carbazolium Salts Using Substituent Electronic Effects.
Increasing the Alkaline Stability of N,N-Diaryl Carbazolium Salts Using Substituent Electronic Effects.
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利用取代基电子效应提高N,N - 二芳基咔唑盐的碱性稳定性
DOI：
10.1021/acsami.0c14132
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发表时间：
2020-11-04
影响因子：
9.5
通讯作者：
Diesendruck CE
中科院分区：
文献类型：
--
作者：
Gjineci N;Aharonovich S;Dekel DR;Diesendruck CE
阴离子交换膜燃料电池（AEMFC）在过去几年中吸引了科学界的注意，主要是因为它有可能消除电池中使用昂贵的铂催化剂的需要。然而，AEMFC的广泛商业化受到电池中氢氧根离子运输所需的阴离子传导膜中阳离子官能团的低化学稳定性的阻碍。提高这些基团的稳定性与识别OH-攻击的不同机制的能力直接相关。在这项工作中，我们已经合成了八个不同的咔唑阳离子模型分子，并研究其碱性稳定性作为其电子取代基的功能特性。鉴于N，N-二芳基咔唑鎓盐通过单电子转移机制分解，咔唑鎓电子密度的变化对其化学稳定性产生非常显著的影响。具有非常负的Hammett参数的取代基对干燥氢氧化物表现出无与伦比的稳定性。本研究提供了一种不同的方法来开发稳定的季铵盐AEMFC的指导方针，利用这种分解机制的独特参数。
Anion-exchange membrane fuel cells (AEMFCs) have attracted the attention of the scientific community during the past years, mostly because of the potential for eliminating the need for using costly platinum catalysts in the cells. However, the broad commercialization of AEMFCs is hampered by the low chemical stability of the cationic functional groups in the anion-conducting membranes required for the transportation of hydroxide ions in the cell. Improving the stability of these groups is directly connected with the ability to recognize the different mechanisms of the OH– attack. In this work, we have synthesized eight different carbazolium cationic model molecules and investigated their alkaline stability as a function of their electronic substituent properties. Given that N,N-diaryl carbazolium salts decompose through a single-electron-transfer mechanism, the change in carbazolium electron density leads to a very significant impact on their chemical stability. Substituents with very negative Hammett parameters demonstrate unparalleled stability toward dry hydroxide. This study provides guidelines for a different approach to develop stable quaternary ammonium salts for AEMFCs, making use of the unique parameters of this decomposition mechanism.
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影响因子：
8.6
作者：
Dekel, Dario R.;Amar, Michal;Diesendruck, Charles E.
通讯作者：
Diesendruck, Charles E.
影响因子：
2.8
作者：
Gjineci, Nansi;Aharonovich, Sinai;Diesendruck, Charles E.
通讯作者：
Diesendruck, Charles E.
影响因子：
8.4
作者：
Marino, M. G.;Kreuer, K. D.
通讯作者：
Kreuer, K. D.
影响因子：
17.6
作者：
Miller, Hamish A.;Vizza, Francesco;Dekel, Dario R.
通讯作者：
Dekel, Dario R.
影响因子：
9.2
作者：
Dekel, Dario R.;Rasin, Igal G.;Brandon, Simon
通讯作者：
Brandon, Simon