质子交换膜燃料电池催化剂研究

质子交换膜燃料电池(PEMFC)的有效电催化剂仍以铂为主.由于铂价格昂贵,资源匮乏,使得PEMFC成本高,限制了其广泛应用,所以降低贵金属催化剂用量,寻找廉价催化剂,提高电极催化剂性能成为电极催化剂研究的主要目标.采用铂/碳催化剂,将铂催化剂担载在高活性碳材料上,可以将铂的担载量从4 mg/cm2降低到0.7 mg/cm2～1.0 mg/cm2,甚至到0.05 mg/cm2～0.2 mg/cm2,有效提高了铂的利用率.铂合金电催化剂以Pt-Ru为主,通过Pt和Ru的协同作用,大大减少了铂的用量(Pt与Ru的质量比为0.05:1),提高了催化剂抗CO性能.多元复合催化剂和非铂系催化剂也是目前的研究热点.     

质子交换膜燃料电池催化剂研究

质子交换膜燃料电池（PEMFC）的有效电催化剂仍以铂为主。由于铂价格昂贵，资源匮乏，使得PEMFC成本高，限制了其广泛应用，所以降低贵金属催化剂用量，寻找廉价催化剂，提高电极催化剂性能成为电极催化剂研究的主要目标。采用铂／碳催化剂，将铂催化剂担载在高活性碳材料上，可以将铂的担载量从4mg／cm^2降低到0．7mg／cm^2～1．0mg／cm^2，甚至到0．05mg／cm^2～0．2mg／cm^2，有效提高了铂的利用率。铂合金电催化剂以Pt-Ru为主，通过Pt和Ru的协同作用，大大减少了铂的用量（Pt与Ru的质量比为0．05：1），提高了催化剂抗CO性能。多元复合催化剂和非铂系催化剂也是目前的研究热点。     

我国CCM型膜电极研究取得重大进展

膜电极是质子交换膜燃料电池(PEMFC)的核心部件,直接影响电池输出性能和反应效率,开发低铂(Pt)担量、高反应效率的CCM(催化剂制备到膜上)型薄催化层膜电极是目前质子交换膜燃料电池开发的一个重要技术方向。在863计划电动汽车重大项目支持下,大连化物所承担的"下一代燃料电池系统研究与开发"课题目前取得重大突破和阶段性成果。     

质子交换膜燃料电池催化剂纳米铂材料研究进展

提高活性、降低贵金属担载量是质子交换膜燃料电池(PEMFC)催化剂的重点研究内容,纳米铂材料是提高阴极氧还原反应(ORR)活性的核心研究方向之一。基于对104篇文献的分析,综述了纳米铂颗粒的粒径、晶面和形貌对催化剂的活性和寿命的影响,以及纳米铂合金的成分和核-壳结构等因素对催化性能的影响。分析现有方法技术的优点和不足,提出催化剂有序化结构和优化ORR反应过程的研究方向。     

质子交换膜燃料电池改性铂基催化剂研究进展

质子交换膜燃料电池(PEMFC)由于其工作效率高、启动速度快、环境友好等优点而倍受青睐。所用催化剂中的核心组分(金属铂)的成本和催化性能是制约其实现商业化的关键因素之一。目前有关改性铂基催化剂应用于质子膜燃料电池的研究工作主要集中在2个方面：一是通过改性催化剂的结构降低铂用柎;二是改性载体材料制备活性组分高度分散的高性能催化剂。综述柚近年来质子膜交换燃料电池改性铂基催化剂的研究进展,并对PEMFC催化剂的发展做柚展望。     

直接甲醇燃料电池活化过程中膜电极变化

采用水煮电极和恒压放电两种方法活化膜电极(MEA),考察了活化前后膜电极及电极上阳极(PtRu/C)与阴极(Pt/C)催化剂的变化情况.电极极化曲线、电化学阻抗谱(EIS)测试发现,活化后的电极性能有较大提高,膜电极的电阻降低.X射线衍射(XRD)的分析表明膜电极上阳极和阴极催化剂都发生聚集长大.分别采用CO吸附溶出法和氢吸脱附法测量MEA的阳极和阴极催化剂的电化学活性面积(ESA),结果表明,尽管催化剂的颗粒长大,但经过恒压放电活化的阳极和阴极的电化学活性面积分别提高了20.9%和5.0%.同时发现恒压放电活化的方法相对于水煮电极活化的方法更有利于提高膜电极性能.     

质子交换膜燃料电池电催化剂的研究现状与展望

概述了质子交换膜燃料电池电催化剂的研究进展以及制备技术,就质子交换膜燃料电池(PEMFC)的发展前景提出了作者的看法。     

Pt-Pd/C催化剂的金属分散度

通过分析炭载贵金属催化剂金属分散度的计算、测试方法，对较少涉足研究的高比表面和高贵金属担载量的Pt-Pd／C催化剂的金属分散度的测试、计算进行了初步的探索，提出了高比表面、高金属担载量和双主份活性元素对金属分散度计算影响机制的新观点。     

质子交换膜燃料电池用Pt-Ag-Co/C催化剂的耐久性研究

研究了两步法制备的质子交换膜燃料电池(PEMFC)用Pt-Ag-Co/C催化剂的耐久性。循环伏安曲线测试表明Pt-Ag-Co/C催化剂与商业Pt/C催化剂的电催化活性相当。通过对扫描500次的循环伏安曲线分析,计算出Pt/C和Pt-Ag-Co/C催化剂扫描前后电化学活性面积(ECA),进而研究了催化剂在PEMFC中的耐久性。结果表明,耐久性实验后Pt/C催化剂的ECA降低了87%;而Pt-Ag-Co/C催化剂仅降低了35%。研究表明微量Co的添加有效的提高了Pt-Ag/C催化剂的耐久性。     

质子交换膜燃料电池金属双极板材料研究进展

双极板在质子交换膜燃料电池(PEMFC)中具有隔离反应介质、收集电流、提供气体通道的作用，金属材料用于双极板面临腐蚀及表面层钝化影响电池性能等问题．在介绍了研究金属双极板性能的方法，包括接触电阻测试、电池极化性能测试、模拟电化学方法等测试方法的同时，着重介绍了在双极板中应用的不同种类铁基金属材料、轻金属材料的性能及各种表面涂层技术的研究进展．简单介绍了PEMFC中，金属双极板材料研究所应重点解决的技术问题．     

Development of a kilowatt class PEMFC stack using Au-coated LF11 Al alloy bipolar plates

Investigations on alternative material for bipolar plates of PEMFC (polymer electrolyte membrane fuel cell) are becoming a research hotspot for many fuel cell researchers. In this paper, LF11 Al alloy bipolar plates via a surface plasma Au plating preparation were applied as bipolar plates. Performances and duration times of PEMFC single cells using graphite; Au-coated LF11 Al bipolar (ALABP) and Au-coated 316L stainless steel plates were compared. It was shown that ALABP exhibited preferable properties. Based on the preparations illustrated above, a kilowatt class proton exchange membrane fuel cell stack consisting of 30 cells was successfully assembled. Pure hydrogen and air were used as the fuel and oxidant, respectively, in the stack. External humidification was employed and cycle cooling water was used to remove the heat from the reaction in order to maintain a constant temperature. A Nafion 1135 membrane and Johnson-Matthy platinum on carbon with a Pt loading of 0.4 mg/cm² were adopted as the electrolyte and catalyst, respectively. The working temperature of the stack ranged from 25 to 100°C. The stack typically worked well under conditions in which the pressure ratio of H₂/air was 0.2/0.22 MPa. The output power, current and voltage were 1–1.3 kW, 40–80 A, and 26–20 V, respectively. The normal current density of the electrode was 200–800 mA/cm², and the energy efficiency of the stack was 51%.     

质子交换膜燃料电池膜电极组件研究进展综述

燃料电池具有能量密度高、利用率高和清洁安静等优点,质子交换膜燃料电池因能够在近常温条件下工作而备受关注,其中膜电极是燃料电池的核心部件。综述了质子交换膜燃料电池膜电极组件的研究进展,从质子交换膜、催化层和气体扩散层3方面阐述各部件在膜电极中的作用,及其对膜电极性能的影响,并讨论通过调控膜电极中不同部件的结构提高膜电极性能的方法,提高贵金属催化剂的利用率,降低膜电极组件中贵金属用量。     

直接甲醇燃料电池关键材料的表面改性及其研究进展

直接甲醇燃料电池(DMFC)由于结构简单、能量密度大、无污染等优点,已经成为近年来国内外研究的热点之一。简要介绍了直接甲醇燃料电池的原理,重点概述了阳极催化剂和电解质膜这两个决定电池性能的关键材料的表面改性及其研究进展。介绍了提高直接甲醇燃料电池阳极催化剂催化活性的各种改性技术,如通过离子溅射法、分子束法等传统物理方法对电极表面进行修饰,在电极材料中掺杂对甲醇催化活性较好的纳米材料等。此外,还介绍了基于降低甲醇渗透率的Nafion膜改进技术,如通过等离子蚀刻法等物理手段对膜表面进行改性,掺杂阻醇性能较好的无机化合物等。并介绍了几种具有应用前景的新型替代膜,如接枝膜、共混膜等。最后对直接甲醇燃料电池的发展应用进行了展望。     

Optimum content of Nafion ionomer for the fabrication of MEAs in PEMFCs with spray-coated Pt/CNT electrodes

To enhance the performance of a polymer electrolyte membrane fuel cell (PEMFC), a Pt catalyst was supported on carbon nanotubes (CNTs) and the optimum content of Nafion ionomer in the Pt/CNT electrode was examined by cell performance tests, cyclic voltammetry, and electrochemical impedance spectroscopy. The amount of the Pt catalyst supported on the CNTs was 34 wt.%. The Nafion content significantly changed the protonic and electronic conductivities as well as the mass transfer properties. As such, the performance of the cell was highly dependent on the content of Nafion ionomer. The results of the cell performance tests revealed that the optimum content of Nafion ionomer in the Pt/CNT electrode was about 20 wt.%.     

Preparation of Pt-based ternary catalyst as cathode material for proton exchange membrane fuel cell by solution route method

In this research, Pt-based ternary catalysts for proton exchange membrane fuel cell (PEMFC) have been successfully prepared by the solution route method. This type of catalyst was claimed to improve the activities of oxygen reduction reaction (ORR). The ternary catalyst was prepared using 10% platinum, 5% cobalt, and 5% chromium by weight support on untreated and treated carbons by reduction with NaBH₄ at room temperature. The FTIR spectra showed a new functional group as carboxyl group on treated carbon using H₂O₂. The XRD patterns for both carbon samples confirmed platinum and carbon phases in the products. The EDS spectra detected platinum, cobalt, chromium, oxygen and carbon atoms in the prepared catalysts. The XAS patterns revealed that the products were mixed Pt-CoO-Cr₂O₃ catalysts. The SEM and TEM images showed more dispersion of catalyst on the treated carbon support surface than on the untreated carbon support. Particles size were 3.97 nm for untreated carbon and 1.93 nm for treated carbon. Finally, the electrochemical property was tested by CV technique. It indicated that Pt-CoO-Cr₂O₃/C catalyst supported on treated carbon exhibited the highest performance among the prepared ternary alloy catalysts.     

酸处理对PtCuLaO_x/C复合薄膜材料电催化性能的影响(英文)EI北大核心CSCD

如何提高Pt在薄膜电极上的利用率是相关研究的热点。本研究采用离子束溅射沉积技术(IBS),在石墨纤维布基底表面制备了PtCuLaOx复合薄膜催化电极材料。采用X射线衍射仪(XRD)及原子力显微镜(AFM)分析了薄膜物相组成及表面结构。在三电极密封电解池体系中采用循环伏安法(CV)和线性扫描伏安法(LSV)分析不同酸处理条件对薄膜电催化性能的影响。结果表明,PtCuLaOx薄膜的晶粒尺寸在30 nm左右,经酸处理后晶粒尺寸变大。在温度50℃,0.5 mol/L的H2SO4溶液中经30 min后处理的薄膜样品,其电化学活性比表面积(ESA)和交换电流密度(i0)均为最高,其载铂量仅为0.0802 mg/cm2,具有很高的性价比。     

热处理对Pt纳米线电催化性能的影响

采用阳极氧化铝(AAO)模板法电化学沉积制备了Pt纳米线催化剂,并进行了热处理。通过X射线衍射(XRD)、扫描电子显微镜(SEM)和电化学测试对热处理前后Pt纳米线催化剂的晶体结构、形貌和电催化性能进行了表征,并与商业碳载铂(Pt/C)做对比。SEM照片表明制备了表面粗糙的Pt纳米线。循环伏安法(CV)和计时电流曲线表明,Pt纳米线较Pt/C催化活性高,退火后Pt纳米线更利于甲醇氧化,且稳定性更好。旋转圆盘电极(RDE)测试研究发现,未经热处理的Pt纳米线催化剂氧还原反应(ORR)极化曲线的半波电势相对Pt/C有正移,有更大的极限扩散电流,利于氧还原反应的发生。     

PtCoCr catalysts for fuel cell cathodes: Electrochemical activity, Pt content, substrate nature, structure and corrosion properties

Creation of multicomponent catalytic systems is the main way to decrease the content of or completely replace Pt in fuel cell cathodes. Compared to the conventional catalytic systems, production of PtCoCr catalysts on different substrates (XC-72 carbon nanotubes, TiO₂) differs in high-temperature conditions and the use of nitrogen-containing transient-metal precursors. According to electrochemical and structural studies, during synthesis and subsequent treatment, alloy nanoparticles with a core-shell structure enriched in platinum are formed on a carbon material doped with nitrogen. The ligand effect of the alloy core results in an increase in the electron density of the platinum d-level, acceleration of oxygen reduction, and deceleration of water molecule discharge and platinum corrosion. A architecture of membrane electrode assembly involving PtCoCr-based active layers of varying composition is developed for fuel cells operating at a temperature of 65°C in hydrogen-air and hydrogen-oxygen environments. In both cases, the use of PtCoCr instead of monoplatinum catalysts enabled us to halve the platinum consumption at the same discharge current density and specific power. The results of life testing and potential cycling of membrane electrode assemblies under severe conditions showed that the resistance of PtCoCr systems is not inferior to platinum.