Metal Hydride Confinement in Functionalized Porous Hosts: Tuning Hydrogen Release Thermodynamics and Kinetics

金属氢化物限制在功能化多孔主体中：调整氢释放热力学和动力学

• 批准号: 374669945
• 负责人: Dr. Andreas Schneemann
• 金额: --
• 依托单位: Sandia National Laboratories
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/374669945?language=en
• 关键词: Metal; Hydride; Confinement; Functionalized; Porous

Safe Energy storage is one of the emerging challenges of the energy transition from fossil and nuclear energy towards sustainable energy. Different strategies to store energy are pursued, for instance electrical storage in batteries or chemically in the form of hydrogen. Common approaches to store hydrogen are either by adsorption on porous materials or as metal hydrides. Metal hydrides are promising due to their high gravimetric hydrogen content, however some materials show, unfeasible reaction kinetics and high desorption enthalpies. To tune these properties some approaches have been made, including the addition of catalysts or the nanoconfinement in porous host. In particular, the latter displayed some promising results as the host-guest interactions between hydride and porous host (1) alter the desorption kinetics and thermodynamics substantially and (2) stabilize small hydride particles. Moreover, it was shown that inclusion of heteroatoms into host matrices with the ability to form lewis acid – lewis base complexes tuned the surface of metal hydride particles and significantly altered the hydrogen desorption properties. Within this project the aim is to (1) prepare metal hydride at functionalized porous host composites, (2) fully analyze them with in-situ methods and finally (3) to establish rules for the design of new hydrogen storage materials.The first part of the proposed project will focus on the preparation of different hydride at porous host systems incorporating functional groups, these will include B- and N-doped porous carbons, pyridine and amino containing functionalized metal-organic frameworks as well as boroxine- and triazine-based covalent-organic frameworks. These hosts will be prepared according to the pertinent literature and their content of functional sites will be controlled by the synthesis conditions. The prepared host materials will then be loaded with a range of hydrides and will be fully characterized.The second part of the proposed project will focus on the (in-situ) characterization of the prepared composites, in particular the identification of reaction pathways and intermediates. Methods that will be used for this task are ambient pressure XPS, in-situ X-ray Absorption Spectroscopy and Scanning Transmission X-ray Microscopy. Lastly, from the results found during the first two stages of this research project, it is envisioned to establish rules for the design of new hydrogen storage materials. For this, the most promising composite materials (regarding gravimetric hydrogen content and desorption enthalpies) will be used as a starting point. Furthermore, this work package will be supported with theoretical modelling from collaboration partners of the HyMARC cluster at Lawrence Livermore National Laboratories and Sandia National Laboratories.

安全能源储存是能源从化石能源和核能向可持续能源过渡的新挑战之一。追求不同的策略来存储能量，例如电池中的电存储或以氢的形式化学存储。储存氢的常用方法是通过吸附在多孔材料上或作为金属载体。金属氢化物由于其高重量氢含量而有希望，然而一些材料显示出不可行的反应动力学和高解吸率。为了调节这些性质，已经采取了一些方法，包括添加催化剂或在多孔基质中的纳米限制。特别是，后者显示出一些有希望的结果，氢化物和多孔主体之间的主客体相互作用（1）改变解吸动力学和热力学显着和（2）稳定小氢化物颗粒。此外，研究表明，将杂原子引入具有形成刘易斯酸-刘易斯碱络合物的能力的主体基质中调整了金属氢化物颗粒的表面，并显著改变了氢脱附性能。本项目的目标是（1）在功能化多孔基质复合材料上制备金属氢化物，（2）用原位方法对其进行全面分析，最后（3）为新型储氢材料的设计建立规则。本项目的第一部分将集中于在引入功能基团的多孔基质系统上制备不同的氢化物，这些将包括B-和N-掺杂的多孔碳，吡啶和含氨基的官能化金属有机骨架以及环硼氧烷和三嗪基共价有机骨架。这些主体将根据相关文献制备，其功能位点的含量将通过合成条件控制。然后，将在制备的主体材料中加入一系列的有机化合物，并对其进行充分的表征。拟议项目的第二部分将侧重于对制备的复合材料进行（原位）表征，特别是确定反应途径和中间体。将用于这项任务的方法是环境压力XPS，原位X射线吸收光谱和扫描透射X射线显微镜。最后，根据本研究项目前两个阶段的结果，设想为新储氢材料的设计建立规则。为此，将使用最有前途的复合材料（关于重量氢含量和解吸率）作为起点。此外，该工作包将得到劳伦斯利弗莫尔国家实验室和桑迪亚国家实验室HyMARC集群合作伙伴的理论建模支持。