共查询到18条相似文献,搜索用时 765 毫秒
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直接甲醇燃料电池的阳极采用甲醇作为燃料,阴极采用纯氧或空气作为氧化剂,具有能量密度高、燃料储存方便、结构简单的优点,有望成为下一代小型电子设备的电源。反应物的浓度对直接甲醇燃料电池的性能、效率和燃料利用率等都有很大的影响,因此对燃料电池中反应物的浓度进行准确测量至关重要。本文综述了直接甲醇燃料电池中反应物浓度的测量方法,主要包括化学测量方法和物理测量方法,并对这些测量方法的优缺点、基本原理及适用范围进行了分析和评述。 相似文献
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徐维正 《精细与专用化学品》2006,14(3):26-29
燃料电池包括碱性燃料电池、磷酸燃料电池、熔融碳酸盐燃料电池、固态氧化物燃料电池和质子交换膜燃料电池.质子交换膜燃料电池中的直接甲醇燃料电池技术获得重大突破,可望于近期进入量产和商业化应用阶段,新型膜材料的开发是目前直接甲醇燃料电池研发的关键课题,电催化剂的催化性能对其功能也起着极为重要的作用.Ball、Casio、DFMC、Giner电化学系统、NEC、Polyfuel、三星电子、东芝和Motorola等一些大公司都在积极开展直接甲醇燃料电池的研发工作,并取得很大进展. 相似文献
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徐维正 《精细与专用化学品》2006,(4):26-29
燃料电池包括碱性燃料电池、磷酸燃料电池、熔融碳酸盐燃料电池、固态氧化物燃料电池和质子交换膜燃料电池.质子交换膜燃料电池中的直接甲醇燃料电池技术获得重大突破,可望于近期进入量产和商业化应用阶段,新型膜材料的开发是目前直接甲醇燃料电池研发的关键课题,电催化剂的催化性能对其功能也起着极为重要的作用.Ball、Casio、DFMC、Giner电化学系统、NEC、Polyfuel、三星电子、东芝和Motorola等一些大公司都在积极开展直接甲醇燃料电池的研发工作,并取得很大进展. 相似文献
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为解决直接甲醇燃料电池中甲醇氧化活性低及甲醇穿透问题,提出一种新型的电解重整式甲醇燃料电池系统。在系统中,高温电解重整器重整甲醇为常温燃料电池供氢,燃料电池的部分电能供给电解重整器使用。通过对系统的物料流、焓流、有效能流的分析,确定了系统中的不可逆因素。结果表明:电解重整器电压是影响系统效率的重要参数;升高重整器温度可以显著降低其电压,但必须采用合理的压力、甲醇溶液浓度以抑制甲醇溶液的蒸发,降低热量损失。与传统的直接甲醇燃料电池系统以及高温甲醇热重整联合质子交换膜燃料电池系统相比,该系统性能较高、结构紧凑。 相似文献
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A conventional membrane electrode assembly (MEA) for a direct methanol fuel cell (DMFC) consists of a polymer electrolyte membrane (PEM) compressed between an anode and cathode electrode. Limitations with this conventional design include: cost, fuel crossover, membrane degradation or contamination, ohmic losses and reduced active triple phase boundary (TPB) sites for catalyst located away from the electrode/membrane interface. In this work, ex situ and in situ characterization of a novel electrode assembly based on a membraneless architecture and advanced 3D anodes was investigated. The approach was shown to be fuel independent and scaleable to a conventional bi-polar fuel cell arrangement. The membraneless configuration exhibits comparable performance to a conventional ambient (25 °C, 1 atm) air-breathing DMFC. However, it has the additional advantages of a simplified design, the elimination of the membrane (a significant component expense) and enhanced fuel and catalyst utilization through the extension of the active catalyst zone. 相似文献
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对直接甲醇燃料电池溶胶-凝胶流动相的制备工艺进行了分析,采用溶胶-凝胶法以正硅酸甲酯为前驱体制备出了溶胶-凝胶流动相.分别以溶胶-凝胶流动相和液体流动相为燃料对比研究了直接甲醇燃料电池的放电性能,测定了溶胶-凝胶流动相在Nation117膜中的甲醇渗透率,研究了溶胶-凝胶流动相的质子电导率.实验结果表明,使用溶胶-凝胶... 相似文献
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在直接甲醇燃料电池(DMFC)中,阳极催化层表面反应生成的CO2气体通过扩散层,及时排出阳极通道,对提高DMFC电流密度具有重要意义,因此研究气泡脱离孔口的过程很有益。今采用Fluent6.2.16对CO2气泡脱离扩散层孔口过程、两孔时气泡形成及聚并过程进行了数值模拟,考察了阳极通道内液体流速、扩散层孔道直径等因素对气泡脱离的影响。结果表明,阳极通道内液体流速越大,气泡脱离扩散层孔口所需的时间越短;扩散层孔道直径越大,气泡脱离扩散层孔口所需的时间越长,且生成的气泡越大;由于从相邻两扩散层孔道出来的气泡的阻挡和挤压作用,使得两气泡周围的压力分布与单气泡不同,气泡脱离过程与从单个扩散层孔口的脱离过程有所不同,脱离时间更早。 相似文献
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综述了近年来低温燃料电池,如质子交换膜燃料电池(PEMFC)和直接甲醇燃料电池(DMFC)催化剂的研究进展,着重介绍了近年来出现的几种制备高分散和高活性的燃料电池催化剂的新技术和新方法,以及关于低Pt和非Pt催化剂的研究情况,简要介绍了关于燃料电池催化剂基础研究方面的情况。 相似文献
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N. Nambi Krishnan Hyoung-Juhn Kim Jong Hyun Jang EunAe Cho Sang-Yeop Lee Tae-Hoon Lim Seong Ahn Hong 《Polymer Bulletin》2009,62(4):457-468
The potential-current fuel cell characteristics of membrane electrode assemblies (MEAs) using hexafluorinated sulfonated poly(ether sulfone) copolymer are compared to those of Nafion® based MEAs in the case of proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC). The hexafluorinated copolymer with 60 mol% of monosulfonated comonomer based acid form membrane is chosen for this study due to its high proton conductivity, high thermal stability, low methanol permeability, and its insolubility in boiling water. The catalyst powder is directly coated on the membrane and the catalyst coated membrane is used to fabricate MEAs for both fuel cells. A current density of 530 mA cm?2 at 0.6 V is obtained at 70 °C with H2/air as the fuel and oxidant. The peak power density of 110 mW cm?2 is obtained at 80 °C under specific DMFC operating conditions. Other electrochemical characteristics such as electrochemical impedance spectroscopy, cyclic voltammetry, and linear sweep voltammetry are also studied. 相似文献
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This work reports on the oxygen reduction activity of several non-precious metal (non-PGM) catalysts for oxygen reduction reaction (ORR) at the fuel cell cathode, including pyrolyzed CoTPP, FeTPP, H2TMPP, and CoTMPP. Of the studied catalysts, pyrolyzed CoTMPP (Co-tetramethoxyphenylporphyrin) was found to perform significantly better than other materials. The catalyst underwent a thorough testing in both hydrogen-air polymer electrolyte fuel cell (PEFC) and direct methanol fuel cell (DMFC). It was found that CoTMPP cathode can sustain currents that are only 2-3 times lower than those obtained with a conventional Pt-black cathode in an H2-air PEFC. DMFC experiments, including methanol crossover and methanol tolerance measurements, indicate high ORR selectivity of the CoTMPP catalyst. Based on results obtained to date, the CoTMPP-based catalyst offers promise for the use in conventional and mixed-reactant DMFCs operating with concentrated methanol feeds. However, hydrogen-air fuel cell life data, consisting of over 800 h of continuous cell operation, indicate that improvement to long-term stability of the CoTMPP catalyst will be required to make it practical. 相似文献