金属卟啉负载炭黑电催化剂氧还原性能

合成了四甲氧基苯基钴卟啉（CoTMPP）和四甲氧基苯基铁卟啉（FeTMPP）配合物,分别负载于经过双氧水和硝酸预处理且掺杂了MnO_x的炭载体,用于质子交换膜燃料电池阴极氧还原反应电催化剂.讨论了不同中心金属离子、不同载体、不同预处理方法和不同焙烧温度对催化剂催化活性的影响.通过旋转圆盘电极技术（RDE）和紫外可见光谱（UV-vis）测试,利用循环伏安曲线（CV）和Koutevky-Levich关系式评价了电催化剂对氧还原反应的电催化性能.研究表明,CoTMPP负载于双氧水处理过的炭载体BP 2000上活性最好,焙烧的最佳温度是900℃,同时发现在载体中掺杂MnO_x并没有达到预期效果.     

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...     

PtCu3/PCNFs催化剂的制备及其氧还原性能研究

用静电纺丝法及热处理,制备了通体多孔的纳米炭纤维载体,并用浸渍-还原法在其表面负载PtCu₃纳米粒子,用于质子交换膜燃料电池氧还原反应,研究了不同还原温度对催化剂颗粒大小及催化活性的影响。使用透射电子显微镜(TEM)、X射线衍射(XRD)等对材料的形貌和结构进行表征,并用电化学工作站测试了其氧还原性能。结果表示600℃还原温度下所制备的PtCu₃/PCNFs-600具有比商业铂炭更好的电化学性能,质量比活性和面积比活性分别为商业铂炭的2.95倍和3.28倍,并且加速循环测试后其性能仍然优于商业铂炭,PtCu₃/PCNFs-600表现出优异的ORR活性。     

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。     

炭材料作为电催化剂载体在PEMFC中的应用

综述了电催化剂炭载体材料的研究进展,内容包括炭载体对电催化剂以及质子交换膜燃料电池(PEMFC)性能的影响,和一些其他炭材料(除炭黑外)在电催化剂载体中的应用。     

Pt-SnO2／C催化剂制备及对乙醇电催化性能测试

使用溶胶凝胶法制备了具有电催化活性的Pt-SnO2／C催化剂,并采用XRD、场透射电子显微镜及电化学测试手段对其进行表征。XRD及场发射透射电子显微镜的结果显示所制得的催化剂平均粒径约为4～20nm。采用循环伏安,交流阻抗的测试手段测试了其在乙醇体系中的电催化活性。该催化剂在乙醇电氧化过程中具有很好的稳定性和较高的电催化活性,其电催化活性高于Pt／C。     

氢燃料电池电催化剂研究进展

目前铂（Pt）及其合金仍是氢燃料电池首选催化剂,但是Pt高价格、低储量及循环稳定性差等缺点严重阻碍了氢燃料电池商业化,因此发展低成本、高性能的新型非Pt催化剂和低Pt催化剂是实现氢燃料电池商业化的关键。本文围绕燃料电池催化开发及使用过程中存在的成本、稳定性和毒化问题,回顾了近年来阴离子交换膜燃料电池和质子交换膜燃料电池催化剂分别在提高阳极催化剂活性、降低阴极催化剂成本领域的最新研究进展,包括催化剂的组成、结构以及颗粒尺寸等对催化活性、稳定性的影响。最后针对燃料电池催化剂存在的问题,指出未来应基于原位观测和表征技术加强对碱性氢氧化机理的研究,同时开发高温制备小尺寸高有序度的有序铂合金阴极催化剂的方法是未来的研究重点。     

质子交换膜燃料电池催化剂制备方法

质子交换膜燃料电池(PEMFC)作为一种高效的能量转换装置,具有使用温度低、转换效率高等优点,是电化学和能源科学领域的一个研究热点.本文讲述了PEMFC的概述、工作原理及其研究现状,并着重论述了PEMFC催化剂各种制备方法.     

High Performance by Applying IrCo/C Nanoparticles as an Anode Catalyst for PEMFC

IrCo bimetallic anode catalysts for polymer electrolyte membrane fuel cell (PEMFC) have been synthesized with a modified ethylene glycol method. X‐ray diffraction, TEM, CV, and linear sweep voltammetry results show that after the modification of Co, Ir nanoparticles supported on carbon exhibit high activity for hydrogen oxidation reaction (HOR). The maximum power density of 610.5 mW cm^–2 of a 50 cm² single cell is achieved using 20%Ir–30%Co/C catalyst as the anode, with a loading of 0.2 mg_Ir cm^–2. It is suggested that IrCo/C proposed in this work may be used as anode catalyst of PEMFC.     

组合式再生燃料电池双效氧电极催化剂制备与表征

介绍了组合式再生燃料电池基本特点,简要回顾了组合式再生燃料电池中双效氧电极催化剂研究现状。利用还原沉积法制备了PtIr／C双效氧电极催化剂,对催化剂进行了XRD表征。以三电极体系对催化剂进行了析氧和溶氧双反应的催化活性评价,结果表明：Pt主要催化燃料电池模式下的溶氧反应,而Ir主要催化水电解模式下的析氧反应。     

CO tolerance of PdPt/C and PdPtRu/C anodes for PEMFC

The performance of H₂/O₂ proton exchange membrane fuel cells (PEMFCs) fed with CO-contaminated hydrogen was investigated for anodes with PdPt/C and PdPtRu/C electrocatalysts. The physicochemical properties of the catalysts were characterized by energy dispersive X-ray (EDX) analyses, X-ray diffraction (XRD) and “in situ” X-ray absorption near edge structure (XANES). Experiments were conducted in electrochemical half and single cells by cyclic voltammetry (CV) and I-V polarization measurements, while DEMS was employed to verify the formation of CO₂ at the PEMFC anode outlet. A quite high performance was achieved for the PEMFC fed with H₂ + 100 ppm CO with the PdPt/C and PdPtRu/C anodes containing 0.4 mg metal cm⁻², with the cell presenting potential losses below 200 mV at 1 A cm⁻², with respect to the system fed with pure H₂. For the PdPt/C catalysts no CO₂ formation was seen at the PEMFC anode outlet, indicating that the CO tolerance is improved due to the existence of more free surface sites for H₂ electrooxidation, probably due to a lower Pd-CO interaction compared to pure Pd or Pt. For PdPtRu/C the CO tolerance may also have a contribution from the bifunctional mechanism, as shown by the presence of CO₂ in the PEMFC anode outlet.     

Graphene and Functionalized Graphene Supported Platinum Catalyst for PEMFC

The graphene was synthesized by chemical oxidation followed by thermal exfoliation of natural graphite. The functionalized graphene (FG) was prepared by chemical treatment of the synthesized graphene. The as‐synthesized graphene and FG were characterized and used as Pt support materials. The 20 wt.% Pt/G and 20 wt.% Pt/FG catalysts were prepared by precipitation method. The prepared catalysts were characterized for particle size using X‐ray diffraction, surface morphology, electrochemical performance, and stability using cyclic voltammetry. The electrochemical surface area of the FG supported platinum catalyst was found to be more than 45% as compared to the commercial carbon supported platinum catalyst. The stability of the developed catalyst (Pt/G and Pt/FG) was significantly higher than the commercial Pt/C. The membrane electrode assembly was developed using the catalysts and tested in a PEMFC. The maximum power densities of the fuel cell were found to be 314, 426, and 455 mW cm^–2 using Pt/C, Pt/G, and Pt/FG, respectively.     

A three-dimensional numerical simulation of the transport phenomena in the cathodic side of a PEMFC

A three-dimensional numerical model is developed to simulate the transport phenomena on the cathodic side of a polymer electrolyte membrane fuel cell (PEMFC) that is in contact with parallel and interdigitated gas distributors. The computational domain consists of a flow channel together with a gas diffusion layer on the cathode of a PEMFC. The effective diffusivities according to the Bruggman correlation and Darcy's law for porous media are used for the gas diffusion layer. In addition, the Tafel equation is used to describe the oxygen reduction reaction (ORR) on the catalyst layer surface. Three-dimensional transport equations for the channel flow and the gas diffusion layer are solved numerically using a finite-volume-based numerical technique. The nature of the multi-dimensional transport in the cathode side of a PEMFC is illustrated by the fluid flow, mass fraction and current density distribution. The interdigitated gas distributor gives a higher average current density on the catalyst layer surface than that with the parallel gas distributor under the same mass flow rate and cathode overpotential. Moreover, the limiting current density increased by 40% by using the interdigitated flow field design instead of the parallel one.     

Pt0．55Co0．45合金应用不同的碳基体作为质子交换膜燃料电池阴极催化剂的研究

分别选用VulcanXC-72和双壁碳纳米管（DWCNTs）作为碳基体,采用化学还原法制备了20％的Pt0.5Co0．45／C催化剂。合成的材料Pt055co0.45／C采用XRD和TEM手段进行表征,电化学性能通过循环伏安（CV）和稳态技术进行了检测。电化学测试结果表明,Pr0.55Co0.45／DWCNTs对氧还砸催化性能优于Pt055C0045／VulcanXC-72,并HDWCNTs具有比VulcanXC．72更好的稳定性。这说明DWCNTs是比VulcanXC－72更有效地催化剂载体。     

Carbon-supported hafnium oxynitride as cathode catalyst for polymer electrolyte membrane fuel cells

Highly stable carbon-supported hafnium oxynitride (HfO_xN_y-C) was synthesized by heating carbon-supported hafnium oxide, prepared using an impregnation method, under NH₃ gas in various conditions. X-ray diffraction patterns, X-ray photoelectron spectra, and field-emission transmission electron microscope images confirmed that HfO_xN_y nanoparticles were dispersed onto commercial carbon black, Vulcan XC-72. The stability of HfO_xN_y-C in 0.1 mol dm⁻³ H₂SO₄ at 303 K was evaluated by measuring the mass ratio of dissolved hafnium to immersed HfO_xN_y-C using inductively coupled plasma atomic emission spectroscopy. It saturated at a low level of 0.8–4.0 mg g⁻¹ with increasing immersion time up to ∼24 h. The oxygen reduction reaction (ORR) activity and rate were evaluated by obtaining cyclic voltammograms and rotating disk electrode voltammograms, respectively. The HfO_xN_y-C exhibited higher ORR activity and a lower Tafel slope than NH₃-treated C under identical conditions, demonstrating that HfO_xN_y is active toward ORR. The ORR activity most depended on the heating temperature. The ORR rate increased with increasing the heating time at 1223 K which could be due to the increased y in HfO_xN_y-C. The maximum onset potential for ORR was 0.78 V vs. standard hydrogen electrode, which is 0.18 V lower than that of carbon-supported platinum.     

微流控法合成石墨烯负载的PtNi燃料电池阴极催化剂及其性能

利用微流控法,以氯铂酸和氯化镍为金属前驱体、硼氢化钠为还原剂,一步合成了石墨烯负载的铂镍燃料电池催化剂,对其进行了表征. 结果表明,在超声辅助条件下,聚乙烯吡咯烷酮为保护剂时,用微流控法可在数秒内得到分散性良好且形貌均一的PtNi/graphene电催化剂,PtNi纳米颗粒的平均粒径为2.1 nm,Pt含量为25.5%(w), 0.7 V (vs. NHE)电压下,电流密度达-107.6 mA/mg,是商业Pt/C(-37.9 mA/mg)的2.8倍,表现出良好的电化学催化活性.     

用于PEMFC的介孔碳担载铂氧化钨电催化剂的制备与表征

利用介孔碳作为载体,制备介孔碳担载Pt-WO3复合催化剂应用于质子交换膜燃料电池（PEMFC）电极.以苯为碳源,采用气相沉积法复制介孔SiO2Al-SBA-15模板结构合成石墨化介孔碳Cg,采用浸渍法制备无定形介孔碳CMK-3.通过分步沉积,将Pt和WO3担载到介孔碳载体上,采用比表面分析（BET）、X线衍射（XRD）、透射电子显微镜（TEM）、循环伏安法以及单电池极化性能测试对介孔碳担载的复合催化剂进行表征.结果表明：介孔碳作为催化剂载体,其孔道结构有助于催化剂的均匀分散,从而提高催化剂的电催化剂活性.由于石墨化介孔碳的导电性能高于无定形介孔碳,因此Pt-WO3/Cg比Pt-WO3/CMK-3具有更好的电极催化活性.