金属有机框架上利用氢溢流进行储氢的材料制备及其储氢机理的研究

项目名称： 金属有机框架上利用氢溢流进行储氢的材料制备及其储氢机理的研究

项目编号： No.20803024

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 李映伟

作者单位： 华南理工大学

项目金额： 18万元

中文摘要： 氢能源是本世纪最有前途的绿色能源，而氢能的有效储存则是氢能应用的关键。利用氢溢流储氢作为有前景的新储氢方法越来越受到关注和重视。项目基于吸附和氢溢流的基本原理，从利用氢溢流储氢的方法出发，以金属有机骨架 (MOFs) 材料为研究对象，系统研究了金属有机骨架上影响其利用氢溢流储氢性能的主要因素及变化规律；密度泛函理论计算和实验结果表明，MOFs材料的金属离子对其利用氢溢流储氢的性能影响不大，而在有机配体上修饰具有吸电子能力的基团能显著提高MOFs材料的氢吸附能和储氢容量。研发了既能高分散地负载具有氢解离能力的金属 (如Pd)，同时又能保持MOFs的结构稳定的储氢材料制备新方法，发现采用过量浸渍法制备的3 wt% Pd/MIL-101材料具有最高的储氢容量。在氢溢流储氢热力学和动力学研究基础上，初步探索了利用氢溢流储氢的机理。通过这些研究可建立利用氢溢流储氢的材料设计和制备思想，拓展金属有机骨架上高效利用氢溢流储氢的材料制备方法，为后续的研究打下基础。

中文关键词： 储氢；氢溢流；催化；金属有机骨架；吸附

英文摘要： Hydrogen energy is considered as one of the most promising green energy in this century. An effective storage for hydrogen is the key to achieve an application of hydrogen. Hydrogen storage by hydrogen spillover is a new and promising method for hydrogen storage, and has attracted considerable interests in recent years. On the basis of the fundamental theories of adsorption and hydrogen spillover, in this study we have focused on the materials of metal-organic frameworks (MOFs) and the method of spillover storage. The effects of surface properties of MOFs on the storage capacities were systematically investigated. The combination of density functional theory (DFT) calculations and experimental results suggests that metal ions in MOFs have a little effect on the hydrogen uptake by spillover, while the organic linkers with electron-withdrawing functional groups can significantly enhance the hydrogen adsorption energy and storage capacity. We have developed a few efficient methods for doping transition metals (such as Pd) on MOFs with high dispersions, while maintaining the structures of the MOFs. It was found that the Pd/MIL-101 material with 3 wt% Pd loading prepared by an excessive impregnation method showed the highest adsorption capacity for hydrogen. After examining the thermodynamics and kinetics of hydrogen spillover, we discussed the mechanism of hydrogen storage by spillover. Through these research, a system for the design and preparation of materials for hydrogen storage by spillover may be established.

英文关键词： Hydrogen storage; Hydrogen spillover; Catalysis; Metal-organic frameworks; Adsorption