金属-有机框架材料在质子交换膜燃料电池中的应用研究进展

Research progress in metal-organic framework materials for proton exchange membrane fuel cells

面对环境污染和能源匮乏,燃料电池作为新型清洁、可再生能源在交通运输、固定与分散电站、移动电源等领域具有广泛的应用前景。然而,目前作为燃料电池核心材料的无机酸或有机质子传导材料存在室温传导率低、湿度依赖性强、构效关系难获得等不足,是制约燃料电池技术发展的一个关键瓶颈。金属-有机框架材料(MOFs)作为一种新型多孔晶态材料,具有结构可设计、骨架可修饰、比表面积大及孔隙可调等优势,在质子传导领域展现出突出的性能和潜在的应用价值。综述了近年来MOFs材料在高性能质子传导方面的研究进展,介绍了质子传导的Grotthuss和Vehicle两种传导机制,系统阐述了有水/无水条件下获得高电导率MOFs质子传导材料的研究方法,详细介绍了高性能、湿度依赖的草酸、羧酸、磷酸和磺酸基MOFs质子传导材料,无水条件下,高性能、高温MOFs质子传导材料通过孔道负载含氮杂环分子获得。最后总结并展望了MOFs质子传导材料未来发展方向,为设计合成性能优异的质子传导MOFs材料提供参考和借鉴。

Fuel cells have potential application in the areas of transportation,stationary and distributed power generation,and portable power sources.In response to environment pollution and limited natural resources,new alternative energy conversion mode has been developed in fuel cells.However,traditional proton conducting materials,such as inorganic acid and organic molecule,generally have low temperature conductivity,high humidity dependence,ambiguously structure-property relationship.The development of fuel cell has been seriously limited because of these deficiencies.Metal-organic framework materials(MOFs)are a new kind of porous crystalline materials with many advantages such as designable structure,modifiable skeleton,large specific surface area and adjustable porosity.Owing to these excellent properties,MOFs show outstanding performance and potential application in the field of proton conduction.In this review,the research progress of high performance proton conduction of MOFs is discussed.Two conduction mechanisms as Grotthuss and Vehicle are introduced.The Grotthuss mechanism is based on the proton transferring process.Hydrogen network has been fabricated through water molecule and provides as pathway to transfer proton.Whereas,the Vehicular mechanism should be ascribed to self-diffusive transport of proton carrier molecules.According to the operating conditions,proton-conducting MOFs can be divided into two types.One works under humidity condition.Proton conduction MOFs based on oxalic acid,carboxylic acid,phosphonic and sulfonic acid have been systematically described.Several strategies can be exploited such as modifying MOFs with functional groups.The high conductivity could be obtained.The other part employs at anhydrous environment.Organic heterocyclic compounds containing nitrogen are loaded into the MOFs channel.The conductivity and work temperature could be improved through this method.Finally,the current issues of high proton conduction MOFs materials is summarized and discussed.The future development is also prospected.This review will provide reference for the design and synthesis of proton conduction MOFs materials with excellent performance.