质子交换膜燃料电池非铂电催化剂研究进展

质子交换膜燃料电池(PEMFCs)目前主要催化剂为贵金属Pt基催化剂。然而,Pt价格高、储量低等问题严重阻碍了PEMFCs的商业化进程。发展低成本、高性能的氧还原催化剂是解决铂资源短缺、降低燃料电池成本、实现燃料电池商业化的关键。结合本课题组的研究工作,综述了最近几年非铂催化剂在燃料电池阴极氧还原方面的研究进展,着重探讨了新型氮掺杂碳基纳米材料的设计与制备,并概述了非铂催化剂面临的困难以及未来发展方向。     

质子交换膜燃料电池Pt基氧还原电催化剂性能提高的策略

铂(Pt)的价格高、储量低,开发优异的Pt基氧还原电催化剂对提高质子交换膜燃料电池(PEMFCs)性能和推动其应用具有十分重要的意义.介绍了Pt基电催化剂活性提高的主要理论,综述了当前电催化剂性能提高的策略,包括电催化剂颗粒尺寸、暴露晶面、晶相和界面对其活性和稳定性的影响,对Pt基电催化剂的发展前景和面临的挑战进行了展...     

低铂燃料电池氧还原催化剂的制备技术研究进展

低铂燃料电池催化剂铂载量低,在具有较高活性的同时能够极大地降低燃料电池的成本,因此,开发低铂燃料电池催化剂一直是燃料电池催化剂的重要研究方向。本文综述了低铂燃料电池催化剂的最新研究进展,对低铂燃料电池催化剂进行了分类,包含Pt基合金结构催化剂、Pt基核壳结构催化剂、Pt单原子层结构催化剂和Pt单原子催化剂等;详细介绍了几种低铂燃料电池催化剂的制备方法,主要包括有机溶胶法、电化学还原沉积法、气相沉积法、原子层沉积法、离子液体法、微波法,并对各自的优缺点进行了总结;重点强调了核壳结构电催化剂的制备方法,包括两步有机溶胶法、脉冲电沉积法、表面去合金化法、欠电位沉积法以及中空构型核壳结构催化剂的制备。最后指出可控制备具有高活性和高稳定性的低铂核壳结构催化剂是质子交换膜燃料电池实现商业化的重要研究方向。     

燃料电池中铂基电催化剂的设计与合成

燃料电池具有高能量转化效率、低环境污染等优势,近年来备受关注。然而,阴极氧还原反应和阳极小分子氧化反应成为燃料电池产业化的瓶颈,包括催化剂制备成本高、催化活性低和稳定性差等问题。如何设计高效、稳定的燃料电池催化剂,对于进一步推动燃料电池的应用十分关键,而发展先进的铂（Pt）基电催化剂是最为有效的途径之一。相比于单金属铂纳米晶,铂基无序合金和有序金属间化合物具有独特的物理化学特性,被认为是研究金属电催化剂结构-性能的理想模型。本文综述了高活性、高稳定性的铂基电催化剂的研究现状,首先阐述了铂基电催化剂的催化活性和稳定性的增强机制,着重介绍了铂基合金的调控因素与可控合成,进一步总结了铂基有序金属间化合物的制备策略。最后,对铂基电催化剂的未来发展方向进行了讨论及展望,以期为燃料电池中电催化剂的发展开拓新思路。     

质子交换膜燃料电池研究进展

质子交换膜燃料电池（proton exchange membrane fuel cell, PEMFC）因具有效率高、功率密度大、排放产物仅为水、低温启动性好等多方面优点,被公认为下一代车用动力的发展方向之一。然而,目前PEMFC在耐久性和成本方面距离商业化的要求还存在一定差距。为攻克上述两大难题,需要燃料电池全产业链的共同努力和进步。本文回顾了近年来质子交换膜燃料电池从催化剂、膜电极组件、电堆到燃料电池发动机全产业链的研究进展和成果,梳理出单原子催化剂、非贵金属催化剂、特殊形貌催化剂、有序化催化层、高温质子交换膜、膜电极层间界面优化、一体化双极板-扩散层、氢气系统循环等研究热点。文章指出,催化层低铂/非铂化、质子交换膜超薄化、膜电极组件梯度化/有序化、燃料电池运行高温化、自增湿化是未来的发展趋势,迫切需要进一步的创新与突破。     

核壳结构低铂催化剂:设计、制备及核的组成及结构的影响

核壳结构低铂催化剂具有可大幅提高贵金属铂的利用率、有效降低燃料电池铂使用量及成本的重要特点,被誉为质子交换膜燃料电池大规模商业化的希望之所在,相关研究已成为燃料电池领域最为热门的课题之一。本文综述了近年来提出的各种高性能核壳结构催化剂的设计思路及新型制备技术,介绍了各种不同组成和结构的核壳结构催化剂性能及特点以及在核壳结构催化剂表征技术方面的最新进展。最后对核壳结构催化剂制备技术的发展和应用前景进行了展望:通过发展或改进制备工艺,制备各种形貌组成可控以及高活性低Pt载量的核壳结构催化剂,有望实现质子交换膜燃料电池商业化。     

高温质子交换膜燃料电池用离子液体聚合物电解质的研究进展

综述了近十几年来高温质子交换膜燃料电池用离子液体聚合物电解质的研究进展及其在高温质子交换膜燃料电池中的应用进展,指出了此类电解质目前存在的亟待解决的两个问题：咪唑类离子液体毒化Pt基催化剂和复合膜中离子液体的长期稳定性。最后对高温质子交换膜燃料电池用离子液体聚合物电解质的发展前景作了展望,即开发与Pt基催化剂相容的离子液体聚合物电解质以及预防复合膜内离子液体的流失,即提高高温质子交换膜燃料电池的性能及长期稳定性,最终提高高温燃料电池的寿命。     

质子交换膜燃料电池研究现状及发展

质子交换膜燃料电池是一种高效清洁的发电技术,具有反应动力学快、启动温度低等特点。目前质子交换膜燃料电池技术发展迅速,有望得到广泛推广和普及。本文从质子交换膜燃料电池核心组件出发,对近年来质子交换膜燃料电池的发展进行了简要概述。从材料出发,对核心组件进行分类,详细介绍了质子交换膜、催化剂以及气体扩散层的研究现状和技术特点,综述了各组件的研究方法、改进方法以及研究进展,展望了质子交换膜燃料电池的研究方向和未来发展趋势。基于高温环境下的各种优势,具有短侧链、低当量的且适用于高温低湿环境的质子交换膜仍将是重点研究对象。质子交换膜燃料电池将进一步向低Pt甚至无Pt方向发展,同时未来将实现无增湿条件下的水平衡。     

铂镍合金催化剂的制备

综述了质子交换膜燃料电池中阳极催化剂和阴极催化剂的进展,介绍了一种能抗CO的阳极催化剂Pt-Ni合金催化剂的制备。     

质子交换膜燃料电池Pt/C催化剂的制备与表征

质子交换膜燃料电池(PEMFC)由于高效、低温快速启动、无污染等优点而受到广泛关注。其中,贵金属铂是PEMFC最常用且高效的电催化材料。以Cabot Vulcan XC-72为碳载体,用多种载体处理法和还原方法置换氯铂酸中的铂,进而合成Pt/C复合催化剂。同时从产率、电催化活性等方面研究了几种方法的优劣性,有较高的实用价值。     

非铂燃料电池电催化剂研究进展

商业铂碳催化剂价格高昂,开发非铂材料是推进燃料电池商业化的关键一步。本文首先介绍了燃料电池氧还原反应电催化剂的研究背景,接着分别介绍了非贵金属、非金属以及复合材料的催化剂,并对各类催化剂的活性位点和催化机理进行了简要的评述。其中,过渡金属的氮碳化物成本低廉,具有较高的催化活性以及优异的稳定性,是最有望替代贵金属Pt的一类催化剂。杂原子的掺杂能够改变碳材料的表面电荷分布,提升碳材料的催化活性。将过渡金属的氮碳化物和特殊结构的碳材料有效结合,可以设计出具有双功能的复合材料。最后,针对非铂催化剂存在的问题进行了分析并提出了今后工作的几个方向,为今后非铂电催化剂的研究提供参考。高活性高稳定性的非铂催化剂是未来该领域的重点研究方向。     

Platinum nanoparticles supported on epitaxial TiC/nanodiamond as an electrocatalyst with enhanced durability for fuel cells

An epitaxial TiC/nanodiamond (ND) was used as novel support for Pt electrocatalysts to improve its durability in fuel cells. The TiC/ND was fabricated by a simple one-pot synthesis method. TiC/ND-supported Pt electrocatalysts were synthesized using a microwave-assisted ethylene glycol method. Pt nanoparticles (NPs) with a mean size of 4.4 nm were highly dispersed on the TiC/ND’s surface. The Pt/TiC/ND catalyst exhibited much higher electrocatalytic activity and stability in methanol oxidation reactions and oxygen reduction reactions than the Pt/ND catalyst. The electrochemical stability of the Pt/TiC/ND catalyst is more outstanding compared with the conventional carbon black supported Pt catalysts. The superior durability can be attributed to the chemical stability of ND core and the anchoring effect of the TiC layer to Pt NPs.     

Hybrid Carbon Supports Composed of Small Reduced Graphene Oxide and Carbon Nanotubes for Durable Oxygen Reduction Catalysts in Proton Exchange Membrane Fuel Cells

We demonstrated highly active and durable hybrid catalysts (HCs) composed of small reduced graphene oxide (srGO) and carbon nanotubes (CNTs) for use as oxygen reduction reaction (ORR) catalysts in proton exchange membrane fuel cells. Pt/srGO and Pt/CNTs were prepared by loading Pt nanoparticles onto srGO and CNTs using a polyol process, and HCs with different Pt/CNT and Pt/srGO ratios were prepared by mechanically mixing the two components. The prepared HCs consisted of Pt/CNTs well dispersed on Pt/srGO, with catalyst HC55, which was prepared using Pt/srGO and Pt/CNTs in a 5:5 ratio, exhibiting excellent oxygen reduction performance and high stability over 1000 cycles of the accelerated durability test (ADT). In particular, after 1000 cycles of the ADT, the normalized electrochemically active surface area of Pt/HC55 decreased by 11.9%, while those of Pt/srGO and Pt/C decreased by 21.2% and 57.6%, respectively. CNTs have strong corrosion resistance because there are fewer defect sites on the surface, and the addition of CNTs in rGO further improved the durability and the electrical conductivity of the catalyst. A detailed analysis of the structural and electrochemical properties of the synthesized catalysts suggested that the synergetic effects of the high specific surface area of srGO and the excellent electrical conductivity of CNTs were responsible for the enhanced efficiency and durability of the catalysts.     

Small Reduced Graphene Oxides for Highly Efficient Oxygen Reduction Catalysts

We demonstrated highly efficient oxygen reduction catalysts composed of uniform Pt nanoparticles on small, reduced graphene oxides (srGO). The reduced graphene oxide (rGO) size was controlled by applying ultrasonication, and the resultant srGO enabled the morphological control of the Pt nanoparticles. The prepared catalysts provided efficient surface reactions and exhibited large surface areas and high metal dispersions. The resulting Pt/srGO samples exhibited excellent oxygen reduction performance and high stability over 1000 cycles of accelerated durability tests, especially the sample treated with 2 h of sonication. Detailed investigations of the structural and electrochemical properties of the resulting catalysts suggested that both the chemical functionality and electrical conductivity of these samples greatly influence their enhanced oxygen reduction efficiency.     

Progress in the synthesis of carbon nanotube- and nanofiber-supported Pt electrocatalysts for PEM fuel cell catalysis

This paper reviews the literature on the synthesis of carbon nanotube- and nanofiber-supported Pt electrocatalysts for proton exchange membrane (PEM) fuel cell catalyst loading reduction through the improvement of catalyst utilization and activity, especially focusing on cathode nano-electrocatalyst preparation methods. The features of each synthetic method were also discussed based on the morphology of the synthesized catalysts. It is clear that synthesis methods play an important role in catalyst morphology, Pt utilization and catalytic activity. Though some remarkable progress has been made in nanotube- and nanofiber-supported Pt catalyst preparation techniques, the real breakthroughs have not yet been made in terms of cost-effectiveness, catalytic activity, durability and chemical/electrochemical stability. In order to make such electrocatalysts commercially feasible, cost-effective and innovative, catalyst synthesis methods are needed for Pt loading reduction and performance optimization.     

Preparation of High Performance Pt/CNT Catalysts Stabilized by Ethylenediaminetetraacetic Acid Disodium Salt

A novel method with ethylenediaminetetraacetic acid disodium salt (EDTA‐2Na) as a stabilizing agent was developed to prepare highly dispersed Pt nanoparticles on carbon nanotubes (CNTs) to use as proton exchange membrane (PEM) fuel cell catalysts. These nanocatalysts were obtained by altering the molar ratio of ethylenediaminetetraacetic acid disodium salt to chloroplatinic acid (EDTA‐2Na/Pt) from 1:2, 1:1, 2:1 to 3:1. The well‐dispersed Pt nanoparticles of around 1.5 nm in size on CNTs were obtained when the EDTA‐2Na/Pt ratio was maintained at 1:1. And the Pt/CNT catalyst exhibited large electrochemical active surface areas, very high electrocatalytic activity and excellent stability in the oxidation of methanol at room temperature. The Pt/XC‐72R catalyst with narrow size distribution was also prepared by this method for comparison purposes. Comparison of the catalytic properties of these catalysts revealed that the activity of the Pt/CNT catalyst was a factor of ∼3 times higher than that of the Johnson Matthey catalyst and ∼2 times higher than that of our Pt/XC‐72R catalyst, which can be assigned to the high level of dispersion of Pt nanoparticles and the particular properties of the CNT supports.     

质子交换膜燃料电池催化剂性能增强方法研究进展

发展低成本、高性能的燃料电池催化剂是实现燃料电池商业化的关键。目前,铂基催化剂仍是动力燃料电池不可替代的主催化剂。本文综述了最近几年燃料电池催化剂增强方面的研究进展,探讨了新型催化剂材料的设计与制备以及提高催化剂活性或稳定性的方法,包括表面修饰、包覆、合金化、几何与电子结构以及晶体结构的调变、催化剂/载体相互作用等手段。开发高活性和高稳定性的非铂类催化剂是燃料电池催化剂的发展趋势和努力方向。其中,提高非铂燃料电池催化剂可靠性、稳定性和活性,迫切需要在燃料电催化理论、非铂催化剂理性设计、燃料电池水热管理、有序化膜电极等方面取得创新和突破。