直接甲醇燃料电池阳极催化剂的研究进展

阳极催化剂是影响直接甲醇燃料电池（DMFC）性能及成本的主要因素之一,从催化剂载体选择、复合催化剂的制备、非贵金属催化剂研究三方面综述了DMFC阳极催化剂国内外研究现状,并进行了简要分析,展望了其应用前景。     

A parametric study of a platinum ruthenium anode in a direct borohydride fuel cell

Data on the performance of a direct borohydride fuel cell (DBFC) equipped with an anion exchange membrane, a Pt–Ru/C anode and a Pt/C cathode are reported. The effect of oxidant (air or oxygen), borohydride and electrolyte concentrations, temperature and anode solution flow rate is described. The DBFC gives power densities of 200 and 145 mW cm⁻² using ambient oxygen and air cathodes respectively at medium temperatures (60 °C). The performance of the DBFC is very good at low temperatures (ca. 30 °C) using modest catalyst loadings of 1 mg cm⁻² for anode and cathode. Preliminary data indicate that the cell will be stable over significant operating times.     

直接甲醇燃料电池(DMFC)改性阳极催化剂的研究进展

介绍了国内外直接甲醇燃料电池（DMFC）的研究状况及其工作原理,阐述了DMFC阳极改性催化剂的作用机理,重点对目前国内外研究的各种改性催化剂体系进行了比较和评价,探讨了电催化剂的发展方向。     

Urchin-like nano/micro hybrid anode materials for lithium ion battery

Inspired by a special biological structure in nature, a kind of urchin-like nano/micro hybrid design was proposed to modify conventional micrometer-sized electroactive materials for lithium ion battery (LIB). By catalytic chemical vapor deposition to in situ grow carbon nanofibers on the surface of natural graphite spheres, we fabricated the nano/micro hybrid composite with an urchin-like structure. Scanning electron microscopy (SEM), focused ion beam (FIB) workstation, transmission electron microscopy (TEM), and Raman spectroscopy were employed to characterize the composite. Electrochemical measurements indicated that the cyclability and rate capability of the composite as anode material for LIB were significantly improved. Furthermore, the design also demonstrated its effectiveness in other kinds of anode materials such as transition metal oxides.     

微生物燃料电池电极材料的最新研究进展

微生物燃料电池（microbial fuel cell,MFC）,是一种同步废水处理与产能的新技术——以微生物为催化剂降解废水中的有机物,将其中的化学能转化为电能。本文介绍了微生物燃料电池阳极和阴极材料以及电极催化剂的最新研究进展,讨论了提高微生物燃料电池性能的方法,即通过使用纳米材料修饰电极来提高微生物及催化剂的吸附面积、结合不同材料的优点制作复合材料做催化剂来克服单一材料的不足之处,以期研究和开发出高性能的微生物燃料电池;指出微生物燃料电池的应用前景是将微生物燃料电池与其它技术相耦合来提前实现它的实际应用。     

锂离子电池负极材料石墨碎除杂整形研究

以石墨电极副产物石墨碎为原料,分别对其进行了除杂与整形研究。除杂过程以浓盐酸为溶剂,采用水浴锅程序升温的方法;整形采用粉碎机粉碎。结果表明,在一定的反应时间和温度下,可达到较好的除杂效果;石墨碎整形后,呈现出圆整的球形或椭球形形貌,振实密度得到提高。     

直接硼氢化物燃料电池阳极电催化剂研究进展

以硼氢化物作为燃料电池的燃料因其高的理论电动势和比能量而引起研究者的广泛关注。理论上,BH-4的电氧化反应为八电子反应,但实际上由于所用阳极电催化剂的不同,BH-4电氧化释放出的电子数也不同。如何抑制BH-4在阳极的水解反应,促进其八电子氧化反应一直是直接硼氢化物燃料电池研究中的核心问题。综述了近几年来国内外在直接硼氢化物燃料电池阳极电催化剂方面所取得的研究进展,并对这一领域中需要深入研究的主要问题进行了论述。     

Polyoxometallate-stabilized platinum catalysts on multi-walled carbon nanotubes for fuel cell applications

A novel catalyst, Pt-PMo₁₂-CNT, with well-dispersed Pt nanoparticles and monolayer PMo₁₂ on multi-walled carbon nanotubes (CNTs) is reported. A polyoxometallate (PMo₁₂) was chemically adsorbed on the surface of Pt nanoparticles and on outer walls of CNTs. These effectively prevented the agglomeration of Pt nanoparticles and CNTs due to the electrostatic repulsive interactions between negatively charged PMo₁₂ monolayers. The as-prepared Pt-PMo₁₂-CNT materials show higher electrocatalytic activity, higher cycle stability, and better tolerance to poisoning species in methanol oxidation than do Pt-CNT catalysts prepared by the same method. The reasons for the improved catalytic performance of the Pt-PMo₁₂-CNT catalysts are discussed.     

石墨烯类材料修饰尿液微生物燃料电池阳极的研究

尿液微生物燃料电池（urine-powered microbial fuel cell,UMFC）能够将尿液中有机物的化学能转化为电能,阳极是影响其产能的关键因素。黑磷（BP）、膨胀石墨（EG）和羧基化石墨烯（COOH-GN）是三种典型的石墨烯类新型材料,分别用这三种材料对阳极碳布进行修饰处理得到了三种电极（BP/CC、EG/CC和COOH-GN/CC）。修饰后的电极表面明显变粗糙,且碳布阳极阻抗均有一定程度的减小。分别以BP/CC、EG/CC和COOH-GN/CC三种电极为阳极运行UMFC,获得的最大电压分别为587.71,512.46和492.49 mV,最大功率密度分别为5254.43,3925.44和3252.05 mW/m³,BP/CC阳极UMFC的性能最好。     

Fibrous MnO2 electrode electrodeposited on carbon fiber for a fuel cell/battery system

A novel fibrous MnO₂ electrode for a fuel cell/battery system is fabricated on carbon fiber by the electrodeposition method. The characteristics of the fibrous MnO₂ electrode are examined by electrochemical impedance spectra, galvanostatic performance and cyclic voltammetry. The experimental results indicate that the fibrous MnO₂ electrodes are superior to pasted electrodes because of the following: (i) better contact between MnO₂ and the electrical conducting material; (ii) high charge-transfer rate because of a smaller diameter than conventional electrodeposited MnO₂ particles (thus it is expected that the specific surface area would be higher); and (iii) a low overpotential. The morphology and the crystal structure of the fibrous MnO₂ electrode are investigated by scanning electron microscopy and X-ray diffraction, respectively. The entire surface of the carbon fiber is found to be coated with γ-MnO₂ after 2 h of electrodeposition at 0.01 A dm⁻² current density.     

直接甲醇燃料电池阳极催化剂研究进展

直接甲醇燃料电池（direct methanol fuel cells, DMFC）由于其高效、清洁等优点,成为替代化石能源的理想新能源装置。催化剂作为DMFC中重要的组成部分,通过降低反应活化能,解决甲醇需要高过电势才能被电氧化的问题。但是目前DMFC阳极催化剂存在催化活性低、抗CO毒性差以及成本较高等问题,限制了DMFC的商业化。本文介绍了甲醇的催化电氧化原理,从Pt基催化剂、非Pt基催化剂、催化剂载体三个方面对DMFC阳极催化剂国内外研究进展进行了综述。介绍了通过选择合适晶面、添加助催化剂、制备特殊形貌、选择合适的载体4种方法对提高催化剂性能、降低催化剂成本的研究现状。甲醇在Pt（100）晶面上的催化活性较好但是抗CO毒性较弱;根据双功能理论和电子调变理论,制备的Pt-M合金催化剂具有更高的抗CO毒性和甲醇催化活性;非Pt基催化剂的制备为降低催化剂成本提供了研究思路;选择合适的催化剂载体,利用载体与催化剂之间的相互作用,也成为解决DMFC阳极催化剂目前面临的易中毒、活性低、成本高等问题的解决方法。     

A nonelectrochemical reductive deposition of ruthenium adatoms onto nanoparticle platinum: anode catalysts for a series of direct methanol fuel cells

The surface of Pt nanoparticles was cleaned and saturated with hydrogen by treatment first with a 3% aqueous solution of H₂O₂ and then with hydrogen gas under water at room temperature. Reaction between the surface hydrogen and aqueous RuCl₃ deposited 0.18 surface equivalents of Ru_ad onto the Pt nanoparticles. The deposition was repeated several times, with each reaction depositing ∼0.18 surface equivalents more Ru_ad onto the Pt-Ru_ad nanoparticles. The resulting Pt-Ru_ad nanoparticles were analysed using cyclic voltammetry, CO stripping voltammetry, and as catalysts for electrooxidation of MeOH in three-electrode experiments and in prototype direct methanol fuel cells. The optimum surface coverage (θ_Ru) for electrooxidation of MeOH was ∼0.33 under these conditions.     

Advanced structures in electrodeposited tin base anodes for lithium ion batteries

A novel composite anode material consisted of electrodeposited Sn dispersing in a conductive micro-porous carbon membrane, which was directly coated on Cu current collector, was investigated. The composite material was prepared by: (1) casting a polyacrylonitrile (PAN)/dimethylformamide (DMF) solution that contained silica particles on a copper foil, (2) removing the solvent by evaporation, (3) dissolving the silica particles by immersing the copper foil into an alkaline solution, (4) drying the copper foil coated by micro-porous membrane, (5) electrodepositing Sn onto the copper foil through the micro-pores in the micro-porous membrane, and (6) annealing as-obtained composite material. This method provided the composite material with high decentralization of Sn and supporting medium purpose of conductive carbon membrane deriving from pyrolysis of PAN. SEM, XRD and EDS analysis confirmed this structure. The characteristic structure was beneficial to inhibit the aggregation between Sn micro-particles, to relax the volume expansion during cycling, and to improve the cycleability of electrode. Galvanostatic tests indicated the discharge capacity of the composite material remained over 550 mAh g⁻¹ and 71.4% of charge retention after 30 cycles, while that of the electrode prepared by electrodepositing Sn on a bare Cu foil decreased seriously to 82.5 mAh g⁻¹ and 13%. These results show that the composite material is a promising anode material with larger specific capacity and long cycle life for lithium ion batteries.     

化学氧化改性微生物燃料电池阳极

浓HNO₃和酸性K₂Cr₂O₇都具有一定的氧化性,分别利用浓HNO₃和酸性K₂Cr₂O₇对阳极碳布进行氧化改性处理。通过红外光谱测试显示,碳布表面附着了羟基(-OH)和羧基(-COOH)。通过扫描电镜观察,碳布经过氧化改性后表面明显变粗糙。同时,循环伏安曲线(CV)和交流阻抗曲线(EIS)测试表明,经过改性后的碳布具有良好的电化学特性。分别以经过浓HNO₃和酸性K₂Cr₂O₇改性处理后的碳布作为微生物燃料电池(MFC)的阳极,获得的最大功率密度分别为291.11 mW·m^-2和438.08 mW·m^-2,比未经过改性处理的碳布阳极的功率密度分别提升了21%和82%。     

Nitrogen‐containing polymeric carbon as anode material for lithium ion secondary battery

Nitrogen‐containing polymeric carbon as anode materials for the lithium ion secondary battery is prepared from polyacrylonitrile (PAN) and melamine–formaldehyde resin (MF) at 600 and 800°C. Its physicochemical properties were investigated through elemental analysis, X‐ray powder diffraction, X‐ray photoelectron spectroscopy, and measurement of specific surface area. Results show that this kind of carbon is amorphous. Nitrogen atoms exist in the prepared polymeric carbon mainly as two states, that is, graphene nitrogen and conjugated nitrogen, and favor the enhancement of reversible lithium capacity. All the prepared polymeric carbon has a reversible capacity higher than that of the theoretic value of graphite, 372 mAh/g, and the highest reversible capacity can be up to 536 mAh/g. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1735–1741, 2000     

Development of anode catalysts for a direct ethanol fuel cell

Ethanol electrooxidation was investigated at platinum based electrodes: Pt, Pt—Sn, Pt—Re dispersed on a high surface area carbon powder. The atomic composition of the bimetallic catalyst was varied and the best results were obtained with an atomic ratio Pt:X close to 100:20. The electrocatalytic activity of Pt, PtSn and PtRe was compared using cyclic voltammetry and long-term electrolyses at constant potential. Under voltammetric conditions and in a single direct ethanol fuel cell, PtSn was the most active catalyst. During electrolysis ethanol was oxidized to acetaldehyde (AAL), acetic acid (AA) and carbon dioxide. On PtSn/C and PtRe/C, the ratio AA/AAL was found to be always lower than unity. Otherwise, PtSn electrocatalysts were the most selective towards the production of CO₂ compared to Pt and PtRe electrodes.     

直接甲醇燃料电池阳极催化剂的制备

直接甲醇燃料电池（DMFC）阳极催化剂是DMFC的关键材料之一,其电化学活性的大小对燃料电池的输出性能及成本起着关键作用。不同催化剂的制备技术决定了催化剂电化学活性的高低。介绍了DMFC阳极催化剂的几种制备方法,并对这些方法进行了评述,对制备DMFC阳极催化剂具有很好的参考价值。     

Preparation of platinum-based electrode catalysts for low temperature fuel cell

We have studied systematically the effects of synthesis parameters in both precipitation and colloidal methods to obtain highly dispersed Pt/carbon catalyst and compared the characteristics of prepared catalysts with commercial ones. The average Pt particle size at optimum condition for 10–60 wt.% Pt/carbon was in the range 1.7–3.8 nm which was about 70–80% of the commercial catalysts at the same Pt loading. The Pt surface area was also 20–40% higher than those of the commercial catalysts. The activities of prepared catalysts, measured by a single cell unit, were comparable with those of commercial ones.     

Synthesis and electrochemical behaviour of tin oxide for use as anode in lithium rechargeable batteries

SnO₂ was synthesized by precipitation from an aqueous solution of SnCl₄ and NH₄OH, followed by a heat treatment. The product was characterized by XRD, SEM, FTIR spectroscopy, DSC and TG. The XRD patterns suggest the formation of phase-pure cassiterite form of SnO₂. SEM imaging indicates that the particles obtained are of sub-micron size with good morphology and size control (around ∼300 nm). Electrodes were fabricated by a slurry-coating procedure and the electrochemical performances of these electrodes were evaluated using galvanostatic cycling tests. The results suggest that the heat treated SnO₂ samples deliver higher capacities when cycled between 1.0 and 0.1 V vs. Li⁺/Li and showed coulombic efficiencies of more than 98% in the tenth cycle.     

A simple model to assess the contribution of alloyed and non-alloyed platinum and tin to the ethanol oxidation reaction on Pt-Sn/C catalysts: Application to direct ethanol fuel cell performance

A simple model is proposed to evaluate the contribution of alloyed and non-alloyed platinum and tin to the ethanol oxidation reaction on Pt-Sn/C catalysts for direct ethanol fuel cells. On the basis of the model, the ethanol oxidation on partially alloyed catalysts occurs through a dual pathway mechanism, separately involving the Pt₃Sn phase and Pt-SnO_x. The model, validated by experimental data, can predict the performance of a single direct ethanol fuel cell by varying the Sn content and/or the degree of alloying of Pt-Sn/C catalysts used as the anode material.