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0引言直接甲醇燃料电池(DMFC)由于其燃料来源丰富、价格低廉、甲醇携带和储存安全方便等独特的优越性而越来越受到重视[1]。但DMFC中常用的阳极Pt催化剂对甲醇氧化的低的电催化活性及易于被甲醇氧化的中间体,吸附态的CO(COad)毒化的问题一直是制约DMFC走向实用化的关键问题[2,3]。由于甲醇分子小,在质子交换膜上有较大的透过作用,并且甲醇具有较高的毒性,所以寻求甲醇的替代燃料也是一直以来被广泛关注的问题[4,5]。乙醇是最简单的链醇分子,相对于甲醇来说,乙醇有很多优点,乙醇基本上没有毒性,来源丰富,价格可与甲醇竞争,能量密度高… 相似文献
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磺化酚酞型聚醚砜膜的制备及其阻醇和质子导电性能 总被引:7,自引:0,他引:7
直接甲醇燃料电池 (Directmethanolfuelcell,DMFC)以高效、清洁和燃料储运方便等优点适宜于作为各种用途的可移动动力源 ,成为 2 0世纪 90年代以来研究与开发的热点[1,2 ] .目前 ,这种电池的研究难点主要集中在催化剂不稳定和质子交换膜透醇上 .一张好的DMFC膜不但要可传递质子、绝缘电子 ,还应具有良好的阻醇性能 .如果膜的阻醇性能不好 ,甲醇会穿过膜到达阴极 ,与氧直接反应而不产生电流 ,不但造成燃料的浪费 ,同时也影响阴极的正常反应 ,使电池效率下降[3 ] .目前广泛应用于燃料电池中的Nafion 系列膜是由美国DuPont公司生产的一种… 相似文献
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生物质基碳材料作为氧还原反应催化剂的研究进展 总被引:1,自引:0,他引:1
燃料电池作为一种清洁能源有很大的发展前景,其阴极氧还原反应多采用铂基催化剂,但由于贵金属铂的储量稀少、价格昂贵等原因,严重阻碍了燃料电池的商业化进程。寻找高活性、高稳定性的新材料来替代阴极铂基催化剂成为燃料电池大规模商业化亟待解决的关键问题之一。研究表明,以生物质为原料的碳材料有望成为商业铂基氧还原催化剂的一种理想替代品。本文综述了这方面的研究进展,并且展望了未来的发展趋势。 相似文献
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对清洁能源替代品的迫切需求推动了人们对燃料电池以及电极催化剂的研究。近年来以改性碳基材料为载体的铂和铂合金催化剂,由于其在大多数燃料电池中性能优异而受到广泛关注。与甲醇和乙醇相比,乙二醇 (Ethylene glycol, EG)很容易从生物质和可再生能源中生产,并且具有优异的反应性能及更高的安全性,是一种很有吸引力的燃料。本文综述了近年来酸性和碱性直接乙二醇燃料电池(Direct ethylene glycol fuel cells, DEGFC)的研究进展,包括DEGFC的结构、铂与不同铂合金在EG中电氧化机理、碳负载铂和铂基EG氧化电催化剂应用特点以及其组装成单电池的性能等等。最后指出了DEGFC发展中需要解决的问题并对未来前景进行了展望。 相似文献
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直接甲醇燃料电池(DMFC)是一种将甲醇燃料的化学能直接转化为电能的能量转换装置,具有能量转化效率高、环境友好、燃料来源丰富等优势,在移动电源等领域具有广泛应用前景,但阳极铂基电催化剂的性能及成本制约着DMFC的发展。本论文通过简单的液相浸渍还原法,制备了系列PtCu/C纳米电催化剂,电化学性能测试结果表明,电催化剂对甲醇氧化反应(MOR)活性顺序为商品Pt/C < Pt3Cu/C < PtCu4/C < PtCu/C < PtCu3/C,且活性最高的PtCu3/C电催化剂表现出较为优异的电化学稳定性。结合物相表征、电化学测试及DFT计算,阐释了PtCu3/C催化剂中存在的少量CuO相能够促进水分子解离产生*OH,通过双功能机制促进类CO反应中间物种氧化为CO2。因此,相比于商品Pt/C,虽然PtCu3/C电催化剂的ECSA不足其一半,但质量比活性和面积比活性分别提高1.88倍和3.74倍。 相似文献
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直接甲醇燃料电池(DMFC)由于其结构简单、能量密度高、易携带、无污染等优点,成为燃料电池未来发展的方向。阳极和阴极催化剂的活性和稳定性是决定DMFC性能、寿命和成本的关键。然而,商业催化剂铂(Pt)的低储量和高成本限制了DMFC的广泛应用,同时,非铂类催化剂的活性和稳定性还需要进一步提高,以达到商业化应用的要求。本文综述了近年来国内外DMFC阳极和阴极催化剂的最新研究进展。首先,对于阳极甲醇氧化催化剂,分别对Pt基催化剂的改性和非Pt类催化剂的研究进展进行了详细介绍;其次,概述了Pt基阴极氧还原催化剂的改性和非Pt阴极催化剂的发展现状;此外,对于催化剂与载体的强相互作用产生的协同效应进行了总结论述;最后,对直接甲醇燃料电池阳极和阴极催化剂的发展前景进行了展望。 相似文献
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Jinwei Chen Chunping Jiang Hui Lu Lan Feng Xin Yang Liangqiong Li Ruilin Wang 《天然气化学杂志》2009,18(3):341-345
Alloying degree, particle size and the level of dispersion are the key structural parameters of Pt-Ru/C catalyst in fuel cells. Solvent(s) used in the preparation process can affect the particle size and alloying degree of the object substance, which lead to a great positive impact on its properties. In this work, three types of solvents and their mixtures were used in preparation of the Pt-Ru/C catalysts by chemical reduction of metal precursors with sodium borohydride at room temperature. The structure of the catalysts was characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). The catalytic activity and stability for methanol electro-oxidation were studied by Cyclic Voltammetry (CV) and Chronoamperometry (CA). Pt-Ru/C catalyst prepared in H2O or binary solvents of H2O and isopropanol had large particle size and low alloying degree leading to low catalytic activity and less stability in methanol electro-oxidation. When tetrahydrofuran was added to the above solvent systems, Pt-Ru/C catalyst prepared had smaller particle size and higher alloying degree which resulted in better catalytic activity, lower onset and peak potentials, compared with the above catalysts. Moreover, the catalyst prepared in ternary solvents of isopropanol, water and tetrahydrofuran had the smallest particle size, and the high alloying degree and the dispersion kept unchanged. Therefore, this kind of catalyst showed the highest catalytic activity and good stability for methanol electro-oxidation. 相似文献
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Influence of copper precursors in the steam reforming of methanol over Cu/SnO2/SiO2 catalysts 总被引:1,自引:0,他引:1
Eun-Ku Lee Hyoung-Sik Kim Kwang-Deog Jung Oh-Shim Joo Yong-Gun Shul 《Reaction Kinetics and Catalysis Letters》2004,81(1):177-181
Cu/SnO2/SiO2 catalysts, prepared with three different copper precursors (copper nitrate, sulfate and chloride), were characterized and investigated for the steam reforming of methanol. Cu/SnO2/SiO2 catalyst, prepared with copper nitrate, showed the highest activity among the tested catalysts. The highest activity of the catalyst prepared with copper nitrate was ascribed to the highly dispersed Cu particles from CO adsorption experiment. The selectivity of methanol to H2 decreased with an increase in the amount of acid on the surface of Cu/SnO2/SiO2 catalysts from FT-IR experiments.This revised version was published online in December 2005 with corrections to the Cover Date. 相似文献
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A carbon supported Pt–Sn electrocatalyst in the Pt/Sn atomic ratio 50:50 was prepared by the reduction of Pt and Sn precursors
with formic acid and thermally treated at 200 °C (i.e., in the presence of solid tin) and 500 °C (in the presence of molten
tin) in flowing hydrogen. In the absence of thermal treatment, X-ray diffraction (XRD) analysis showed a solid solution of
Sn in the face centered cubic (fcc) Pt and SnO2. After thermal treatment, the formation of a main phase of hexagonal PtSn (niggliite) and a secondary phase of cubic Pt3Sn was observed in the Pt50Sn50 catalyst. The relative amount of the PtSn phase increased with increasing thermal treatment
temperature. The presence of molten tin gave rise to the formation of some big particles during annealing at 500 °C. The activity
for the ethanol oxidation reaction (EOR) of the as-prepared catalyst was higher than that of both thermally treated catalysts
and Pt75Sn25/C and Pt50Ru50/C by E-TEK. The higher activity for the EOR of the as-prepared Pt–Sn catalysts was ascribed to
the presence of a large amount of SnO2.
Dedicated to Teresa Iwasita’s 65th birthday. 相似文献
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直接甲醇燃料电池阳极催化剂PtRu/C的制备和表征 总被引:22,自引:2,他引:22
用三种方法制备了PtRu/C[Pt和Ru质量分数分别为20%和10%,记为PtRu/C(20%-10%)]甲醇阳极催化剂,通过X射线衍射(XRD)和透射电镜(TEM)考察了PtRu/C催化剂的粒子大小和晶格参数的变化,利用单电池实验考察了催化剂在直接甲醇燃料电池中的催化活性.结果表明,改变溶剂的组成提高了贵金属在活性炭表面的分散度,并改善了PtRu间的相互作用,用乙二醇/水/异丙醇混合溶剂制备的PtRu催化剂金属颗粒较小,PtRu间的相互作用较强,以该催化剂作甲醇阳极的直接甲醇燃料电池的性能较好. 相似文献
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In a CO−O2 stoichiometric mixture, the kinetic parameters, reaction order, rate constant and activation energy of CO oxidation over
a Pt/SnO2 catalyst have been measured using a fixed bed flow reactor near 0°C. The results show that it is a first-order reaction.
The activation energy of CO oxidation over Pt/SnO2 prepared with SnO2 calcined at 300°C was approximately 21 kJ/mol. The activation energy of CO oxidation over Pt/SnO2 changed slowly with SnO2 calcination temperature above 400°C, and reached approximately 45 kJ/mol. 相似文献
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《Electrochemistry communications》2007,9(10):2541-2546
Carbon-supported Ir3Sn/C and Ir/C catalysts were simply prepared with NaBH4 as a reducing agent under the protection of ethylene glycol at room temperature. TEM and X-ray diffraction (XRD) data showed that the catalysts with small particle size exhibited the typical characteristic of a crystalline Ir fcc structure. Their electro-catalytic activities in comparison with Pt/C and Pt3Sn/C catalysts also prepared by the NaBH4 reduction process were characterized by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and chronoamperometry (CA) techniques. The results indicated that Ir-based catalysts showed superior electro-catalytic activity towards ethanol oxidation to Pt/C and Pt3Sn/C catalysts, mainly at low potential region. During single-cell tests at 90 °C, better performances of Ir-based catalysts as anodes were obtained compared to that of Pt/C catalyst. The comparable overall performance of Ir3Sn/C to Pt3Sn/C makes it a promising alternative choice of anode catalyst for direct ethanol fuel cells. 相似文献
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Mild Synthesis of Pt/SnO2/Graphene Nanocomposites with Remarkably Enhanced Ethanol Electro‐oxidation Activity and Durability
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Dr. Yunteng Qu Dr. Yunzhi Gao Dr. Long Wang Dr. Jiancun Rao Dr. Geping Yin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(1):193-198
We have designed a new Pt/SnO2/graphene nanomaterial by using L ‐arginine as a linker; this material shows the unique Pt‐around‐SnO2 structure. The Sn2+ cations reduce graphene oxide (GO), leading to the in situ formation of SnO2/graphene hybrids. L ‐Arginine is used as a linker and protector to induce the in situ growth of Pt nanoparticles (NPs) connected with SnO2 NPs and impede the agglomeration of Pt NPs. The obtained Pt/SnO2/graphene composites exhibit superior electrocatalytic activity and stability for the ethanol oxidation reaction as compared with the commercial Pt/C catalyst owing to the close‐connected structure between the Pt NPs and SnO2 NPs. This work should have a great impact on the rational design of future metal–metal oxide nanostructures with high catalytic activity and stability for fuel cell systems. 相似文献
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采用脉冲微波辅助化学还原法制备了钴-聚吡咯-碳(Co-PPy-C)载Pt 催化剂(Pt/Co-PPy-C),其中Pt 的总质量占20%. 利用透射电镜(TEM)、光电子射线能谱分析(XPS)和X射线衍射(XRD)研究了催化剂的结构,用循环伏安(CV)、线性扫描伏安(LSV)等方法考察了其电化学活性及氧还原反应(ORR)动力学特性及耐久性. Pt/Co-PPy-C电催化剂的金属颗粒直径约1.8 nm,略小于商用催化剂Pt/C(JM)颗粒尺寸(约2.5 nm);催化剂在载体上分散均匀,粒径分布范围较窄. Pt/Co-PPy-C的电化学活性比表面积(ECSA)(75.1 m2·g-1)高于商用催化剂的ECSA(51.3 m2·g-1). XPS测试表明,自制催化剂表面的Pt 主要以零价形式存在. 而XRD结果显示,自制催化剂中Pt(111)峰最强,Pt 主要为面心立方晶格. Pt/Co-PPy-C具有与Pt/C(JM)相同的半波电位;在0.9 V下,Pt/Co-PPy-C的比活性(1.21 mA·cm-2)高于商用催化剂的比活性(1.04 mA·cm-2),表现出更好的ORR催化活性.动力学性能测试表明催化剂的ORR反应以四电子路线进行. CV测试1000 圈后,Pt/Co-PPy-C和Pt/C(JM)的ECSA 分别衰减了13.0%和24.0%,可见自制催化剂的耐久性高于商用Pt/C(JM),在质子交换膜燃料电池(PEMFC)领域有一定的应用前景. 相似文献