Mileo Paulo G M, Adil Karim, Davis Louisa, Cadiau Amandine, Belmabkhout Youssef, Aggarwal Himanshu, Maurin Guillaume, Eddaoudi Mohamed, Devautour-Vinot Sabine
Institut Charles Gerhardt Montpellier , UMR 5253 CNRS, UM, ENSCM, Université Montpellier, Place E. Bataillon , 34095 Montpellier cedex 5, France.
Functional Materials Design, Discovery & Development Research Group (FMD3), Advanced Membranes & Porous Materials Center, Division of Physical Sciences and Engineering , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Kingdom of Saudi Arabia.
J Am Chem Soc. 2018 Oct 17;140(41):13156-13160. doi: 10.1021/jacs.8b06582. Epub 2018 Oct 6.
A hydrolytically stable metal-organic framework (MOF) material, named KAUST-7', was derived from a structural phase change of KAUST-7 upon exposure to conditions akin to protonic conduction (363 K/95% relative humidity). KAUST 7' exhibited a superprotonic conductivity as evidenced by the impedance spectroscopic measurement revealing an exceptional conductivity up to 2.0 × 10 S cm at 363 K and under 95% RH, a performance maintained over 7 days. Ab initio molecular dynamics simulations suggested that the water-mediated proton transport mechanism is governed by water assisted reorganization of the H-bond network involving the fluorine moieties in KAUST-7' and the guest water molecules. The notable level of performances combined with a very good hydrolytic stability positions KAUST-7' as a prospective proton-exchange membrane alternative to the commercial benchmark Nafion. Furthermore, the remarkable RH sensitivity of KAUST-7' conductivity, substantially higher than previously reported MOFs, offers great opportunities for deployment as a humidity sensor.
一种水解稳定的金属有机框架（MOF）材料，名为KAUST-7'，是由KAUST-7在类似于质子传导的条件（363 K/95%相对湿度）下发生结构相变衍生而来。KAUST 7'表现出超质子传导性，阻抗谱测量表明，在363 K和95%相对湿度下，其电导率高达2.0×10 S cm，性能可持续7天以上。从头算分子动力学模拟表明，水介导的质子传输机制受水辅助的氢键网络重排控制，该氢键网络涉及KAUST-7'中的氟部分和客体水分子。KAUST-7'出色的性能水平以及良好的水解稳定性使其成为商业基准材料Nafion的潜在质子交换膜替代品。此外，KAUST-7'电导率对相对湿度具有显著的敏感性，大大高于先前报道的金属有机框架，这为其作为湿度传感器的应用提供了巨大机遇。
