金属有机框架质子导体及其质子交换膜的研究进展

质子交换膜是新型燃料电池的关键组件之一.以Nafion为代表的商用全氟磺酸质子交换膜成本较高、操作温度较低,限制了宽温度范围下的大规模应用.金属有机框架材料(Metal Organic Framework, MOFs)因其比表面积大、结构规整、可设计性强等优点,在质子交换领域备受关注.作者从三方面综述了MOFs质子导体的相关研究.第一部分主要介绍了MOFs传导质子的作用机理;第二部分从有水/无水条件下工作的两种不同MOFs出发综述了MOFs质子导体的相关发展;第三部分系统回顾了MOFs质子交换膜的相关研究,包括MOFs薄膜与MOFs混合基质膜结构.最后指出了MOFs质子导体及其质子交换膜研究中尚未解决的问题,并展望该领域的未来研究方向.     

固体电解质质子导体的研究进展

介绍了固体电解质质子导体的应用、结构、质子传输机理以及国内外的最新研究进展,详细地综述了钙钛矿型和非钙钛矿型固体电解质质子导体的多种结构类型以及其质子传导机理的最新理论研究,同时分别介绍了两种质子导体的发展概况和面临问题,展望了未来质子导体的发展前景.     

一种新型结构质子交换膜的研究

质子导体的研究近年来受到了广泛的关注，具有质子传导能力的电解质材料可广泛地应用于燃料电池、电解池、电化学反应装置以及传感器等领域，特别是作为质子交换膜燃料电池（PEMFC）的核心组件之一的质子交换膜越来越受到人们的重视。Nafion（Du Pont）全氟磺酸膜是目前广泛用于PEMFC中的一种质子导体。Nafion全氟磺酸膜具有优异的化学稳定性以及在较低温度条件下高的质子电导率，然而其高昂的价格、差的高温性能以及用于直接甲醇燃料电池（DMFC）中时的高甲醇渗透率阻碍了DMFC商业化发展。     

质子交换膜燃料电池膜电极

介绍了质子交换膜燃料电池膜电极的组成，电极反应，综述了近年来膜电极的研制方法。探讨了该电池电极制作过程的关键问题及技术。     

新颖无机质子传导材料的研究进展

质子传导在燃料电池、气体传感及电致显色等领域有重要的研究前景.尤其是在燃料电池领域,由于其具有低污染、高效率、操作简单和寿命长等优点而被广泛应用.本文介绍了质子传导在质子交换膜燃料电池中的重要作用及工作原理,分析了质子交换膜的质子传导机理,并简要分析总结了近年来关于无机及其复合质子导体材料的研究进展.     

质子交换膜燃料电池新结构

质子交换膜燃料电池（ＰＥＭＦＣ）能量效率和功率密度高,无电解质腐蚀,环境友好,可望广泛用于电动汽车的发电装置、便携式电源和地面发电站等．许多发达国家都投巨资对其进行研究开发［１］．传统的单对ＰＥＭＦＣ由膜～电极组件和其两侧的集流板构成,其中膜～电极组...     

化学与生物改性合成质子交换膜*

新型质子交换膜的研究主要集中在Nafion膜的化学或物理改性、化学合成材料的更新以及新型的生物材料燃料电池用质子交换膜的研发。本文对燃料电池用质子交换膜近3年的研究进展做了综述,并对PEMFC质子交换膜的发展前景进行了探讨与预测。     

质子交换膜燃料电池材料

质子交换膜燃料电池是最接近商业化的一种燃料电池,最有希望作为未来电动汽车的发动机,近二十年取得了长足的发展.目前限制质子交换膜燃料电池进入商业化的最主要原因是成本和寿命两大问题,寻找和开发新型材料成为解决这两大问题、推进商业化进程的必然选择,也是质子交换膜燃料电池近些年来的研究重点和热点.本文对构成质子交换膜燃料电池的...     

非含氟型磺化聚合物质子交换膜材料的研究进展(下)

概述了近十年来非含氟型磺化聚合物质子交换膜材料的研究进展,包括各种材料的制备和性质,详细地讨论了材料的化学结构、形态与其性能(质子导电率、耐水性、尺寸稳定性、吸水率、抗自由基氧化性、甲醇透过率等)之间的关系,其中结合作者在磺化聚酰亚胺方面的研究工作,重点对这类材料进行了系统、深入的介绍和讨论.最后,本文还对今后燃料电池用质子交换膜材料的研究提出了一些设想和展望.本文分为上下两篇,其中下篇主要综述了非含氟型磺化聚合物的性能与结构形态之间的关系.     

质子交换膜燃料电池的研究

通过测定电压－电流密度曲线等方法研究质子交换膜燃料电池的电极参数。构造了Ｅｃｅｌｌ＝０．７Ｖ，Ｉ＝０．５５Ａ／ｃｍ＾２并能够稳定运行的燃料电池。改进电池的电极结构，研究了各种操作条件如温度，压力，增湿情况，尾气流量等对电池性能的影响。     

Sol-Gel Synthesis and Characterization of SiO2—P2O5—ZrO2

Zirconia phosphosilicates were prepared by the sol-gel method using tetraethylorthosilicate, triethyl phosphate, and zirconium n-propoxide. Monolithic, transparent gels were formed with 10 mole% ZrO₂, and 10, 20 or 30 mole% P₂O₅. The influence of the mole% P₂O₅, treatment temperature and water content, on thermal behavior, water adsorption, and proton conductivity were studied. A heat treatment at 200°C was effective in removal of residual organics, creating a porous material capable of good water retention upon rehydration.     

Composite polymer electrolyte membranes comprising P(VDF‐co‐CTFE)‐g‐PSSA graft copolymer and zeolite for fuel cell applications

Hybrid organic/inorganic composite polymer electrolyte membranes based on a poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) grafted membrane and varying concentrations of zeolite were investigated for application in proton exchange membrane fuel cells (PEMFC). A proton conducting comb copolymer consisting of poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) backbone and poly(styrene sulfonic acid) (PSSA) side chains, i.e. P(VDF‐co‐CTFE)‐g‐PSSA (graft copolymer) with 47 wt% of PSSA was synthesized using atom transfer radical polymerization (ATRP) and solution blended with zeolite. Upon incorporation of zeolite, the symmetric stretching band of both SO group (1169 cm^?1) and the ? OH group (3426 cm^?1) shifted to lower wavenumbers. The shift in these FT‐IR spectra suggests that the zeolite particles strongly interact with the sulfonic acid groups of PSSA chains. When the weight percent of zeolite 5A is above 7%, the proton conductivity at room temperature was reduced to 0.011 S/cm. The water uptake of the composite membranes decreased from 234 to 125% with an increase of the zeolite 5A weight percent to 10 wt%. The decrease in water uptake is likely a result of the decrease in the number of available water absorption sites because of the hydrogen bonding interactions between the zeolite particles and the graft copolymer matrix. This behavior is successfully investigated by scanning electron microscopy (SEM). The results of thermal gravimetric analysis (TGA) also showed that all the membranes were stable up to 300°C. Copyright © 2009 John Wiley & Sons, Ltd.     

PEMFC薄层金属双极板研究进展

双极板是质子交换膜燃料电池的核心部件,占据电池组重量和成本的绝大部分。本文对铁基合金、镍基合金和铝、钛等轻金属三大类薄层金属板及其表面改性方法进行了详细评述,在此基础上提出了导电化合物和电化学方法对薄层不锈钢改性是今后薄层金属双极板的发展方向。     

微型氢气/空气自呼吸式质子交换膜燃料电池

数码相机、手提电脑和移动电话等各种新型的电子产品对电池的能量要求越来越高．例如,配备最新的Li离子电池的数码相机只能连续工作30min,手提电脑只运行3h．显然传统电池的发展已越来越不能满足便携式电子设备的用电需求．微型质子交换膜燃料电池(μPEMFC)由于具有高比能量、无需充电和无自放电等优点,在便携式电子设备中具有广阔的应用前景．然而,用传统技术制作μPEMFC不能适应PEMFC微型化要求．因此基于微机电系统(MEMS)技术的微型质子交换膜燃料电池(μPEMFC)已成为国际上的研究热点．2000年,Kelley等基于MEMS技术制作了μPEMFC,随后又在30℃,用加湿氢气作燃料,压缩空气为氧化剂(流速为0．2L／min),电池峰值功率约为120mW／cm^2等条件下进一步研究了μPEMFC。     

Effects of Heteropoly Acids and Surfactant on Electrochemiluminescence of Tris(2,2'-Bipyridine) Ruthenium(II)

ABSTRACT

The effects of heteropoly acids and Triton X-100 on electrochemiluminescence (ECL) of Ru(bpy)₃ ²⁺ are investigated. Triton X-100 prevents the oxidation of oxalate and results in an increase of the ECL signal. H₅SiW₁₁VO₄₀ prevents the direct oxidation of oxalate and makes the electrochemical behavior of Ru(bpy)₃ ²⁺ less reversible, which leads to a decrease of the ECL signal. In contrast, H₃PMo₁₂O₄₀ has negligible effect on ECL intensity. Some possible reasons for the effects on the ECL of Ru(bpy)₃ ²⁺ are discussed based on the adsorption of SiW₁₁VO₄₀ ^5? on electrode surface and the ion association between SiW₁₁VO₄₀ ^5? and Ru(bpy)₃ ²⁺. The signal of ECL decreases linearly with the concentration of heteropoly acid in the range from 2x10^?6 to 1x10^?4 mol 1^?1. The results indicate that ECL of Ru(bpy)₃ ²⁺ is a potential sensitive and selective detection method for heteropoly acids and hence for the elements comprised in them.     

Scaling up Studies on PEMFC Using a Modified Serpentine Flow Field Incorporating Porous Sponge Inserts to Observe Water Molecules

Flooding of the cathode flow channel is a major hindrance in achieving maximum performance from Proton Exchange Membrane Fuel Cells (PEMFC) during the scaling up process. Water accumulated between the interface region of Gas Diffusion Layer (GDL) and rib of the cathode flow field can be removed by the use of Porous Sponge Inserts (PSI) on the ribs. In the present work, the experimental investigations are carried out on PEMFC for the various reaction areas, namely 25, 50 and 100 cm². Stoichiometry value of 2 is maintained for all experiments to avoid variations in power density obtained due to differences in fuel utilization. The experiments include two flow fields, namely Serpentine Flow Field (SFF) and Modified Serpentine with Staggered provisions of 4 mm PSI (4 mm × 2 mm × 2 mm) Flow Field (MSSFF). The peak power densities obtained on MSSFF are 0.420 W/cm², 0.298 W/cm² and 0.232 W/cm² compared to SFF which yields 0.242 W/cm², 0.213 W/cm² and 0.171 W/cm² for reaction areas of 25, 50 and 100 cm² respectively. Further, the reliability of experimental results is verified for SFF and MSSFF on 25 cm² PEMFC by using Electrochemical Impedance Spectroscopy (EIS). The use of 4 mm PSI is found to improve the performance of PEMFC through the better water management.     

有机溶剂对PEM燃料电池CCM结构和性能的影响

采用直接喷涂法将催化剂涂覆在质子交换膜上形成CCM(catalyst coated membrane),CCM与碳纸扩散层组成膜电极用于质子交换膜燃料电池.制备CCM的混合液由质量分数20%的Pt/C催化剂、质量分数5%的Nafion溶液、有机溶剂和水组成.不同的有机溶剂(乙醇、异丙醇和叔丁醇)、有机溶剂的含量、溶剂的...     

质子交换膜的传输通道微观结构对燃料电池性能的影响

质子交换膜燃料电池因其高效、高能量密度、快速启动等独特优势在便携电子设备及汽车动力装置等应用中极具发展潜力。质子交换膜内的传输通道由于对膜质子传导性能有重要影响而受到研究者们的广泛关注。构筑有序结构的质子传输通道,能够获得质子电导率与燃料渗透率、热稳定性、化学稳定性等性能均衡提升的新型质子交换膜材料。本文结合近年来质子传输通道的研究进展,对控制聚合物的相形态从而构筑有序质子传输通道的研究进行了综述,并针对不同相形态所形成的有序通道对膜及燃料电池性能的影响进行了分类与评述,最后对其发展趋势进行了展望。