Nickel foam-based composite electrodes for electrooxidation of methanol

Nickel foam and five nickel foam-based composite electrodes were prepared for being used as anode materials for the electrooxidation of methanol in KOH solution containing 0.1 and 1.0 M of methanol. The layered electrodes composed of nickel foam, platinum nanoparticles, polyaniline (PANI) and/or porous carbon (C) prepared in various assemblies. As shown by SEM analysis, depending on the preparation conditions, the electrodes of different morphologies were obtained. Using the cyclic voltammetry method, the oxidation of methanol on nickel foam electrode was observed in the potential range 0.4 V ↔ 0.7 V, where the Ni(OH)₂/NiOOH transformation occurred. The presence of Pt particles in electrode gave rise to the increase in electrocatalytic activity in this potential range. For electrodes containing dispersed platinum catalyst (Ni/Pt, Ni/PANI/Pt and Ni/C/Pt), the oxidation of methanol was noted also in the potential range −0.5 V ↔ 0.1 V. The electrocatalytic activities of the examined electrodes toward methanol oxidation at low potentials were in order Ni/Pt > Ni/C/Pt > Ni/PANI/Pt, whereas at high potentials in order Ni/PANI/Pt > Ni/Pt> Ni/C/Pt > Ni. Among the examined electrodes, the most resistant to cyclic poisoning appeared to be the Ni/C/Pt electrode. Presented at the 4Th Baltic Conference on Electrochemistry, Greifswald, March 13–16, 2005     

低维纳米材料在质子交换膜燃料电池电催化反应中的应用

在聚合物膜燃料电池中,电催化剂决定了电池的运行寿命及性能。本文按照材料维数的不同,分别介绍了近年来零维、一维和二维材料在聚合物膜燃料电池电极反应中应用的最新研究进展;并对各类聚合物膜燃料电池电催化反应的机理和研究侧重点进行了详细的介绍。     

以多聚甲醛为还原剂制备新型阳极Pt/CMK-3催化剂

 以多聚甲醛为还原剂,采用液相还原法制备了Pt/CMK-3直接甲醇燃料电池(DMFC)阳极催化剂,并采用透射电镜和X射线衍射技术对其进行了表征. 结果表明,有序介孔碳CMK-3具有规整的二维有序孔道结构,为DMFC中电子和燃料的传输提供了方便的路径,同时它较大的比表面积使得Pt纳米粒子很好地分散在其表面; Pt/CMK-3催化剂中Pt粒子的平均粒径为2.8 nm, 小于E-TEK公司的商品化Pt/XC-72和以甲醇为还原剂制备的Pt/C-M催化剂,并且粒径分布范围窄,结晶度低. 察了Pt/CMK-3催化剂对甲醇的电催化氧化性能,发现Pt/CMK-3催化剂对甲醇氧化的电催化性能优于Pt/XC-72和Pt/C-M催化剂.     

乙醇在碳修饰的二氧化钛纳米管负载的钯电催化剂上的催化氧化

 通过有机物分解碳化处理TiO2 纳米管制得了TiO2C, 并以其为载体制备了Pd/TiO2C电催化剂,考察了该催化剂对碱性介质中乙醇电催化氧化的活性. 结果表明,碳化导电处理的TiO2C纳米管载体能有效改善催化剂中贵金属的分散度和电极结构,从而提高催化剂的电催化活性. 对催化剂活性组分的优化实验表明, Pd/TiO2C质量比为1/1时催化剂的活性最高. 在1 mol/L KOH溶液中Pd载量均为0.3 mg/cm2的条件下, Pd/TiO2C催化剂对乙醇氧化的催化活性是Pd/C催化剂的3.8倍.     

甲酸作直接甲醇燃料电池替代燃料

甲酸作直接甲醇燃料电池替代燃料;甲醇;甲酸;直接甲醇燃料电池;Pt-Ru/C催化剂     

Xas study of actinide solvent extraction compounds. ii: UO(NO)(L) (with L=tri-isobutylphosphate, tri-n-butylphosphate, trimethylphosphate and triphenylphosphate)

In the back-end of the nuclear fuel cycle, liquid–liquid extraction is the selected separation method. For an improved design of new extracting agent, the knowledge of the coordination polyhedra of the metal ions is important. In this paper, we investigated the coordination sphere of a series of uranyl complexes with selected organophosphorus extracting molecules: UO₂(NO₃)₂L₂ (with L=tri-iso-butylphosphate, tri-n-butylphosphate, trimethylphosphate and triphenylphosphate) using X-ray absorption spectroscopy. FEFF7 calculations of the EXAFS spectra corresponding to the model compound UO₂(NO₃)₂(TiBP)₂ (with TiBP=tri-iso-butylphosphate) for which the crystal structure is known led to a multiple scattering approach of the data fitting. EXAFS results show subtle U–O(P) bond distance differences between the different complexes that are discussed in terms of both electronic and steric effects of L. These results are discussed with regards to the extraction ability of L. In the same time, exploratory work has been attempted in order to evaluate U–O–P bond angle variations as a function of L using multiple photon-scattering paths. Satisfactory values have been obtained compared to the crystallographic data.     

高性能质子交换膜燃料电池

用全氟碘酸质子交换膜作为质子交换膜燃料电池（ＰＥＭＦＣ）电解质,简化了水和电解质的管理。本文研究了该燃料电池质子交换膜厚度对电池性能影响;性能最佳的Ｎａｆｉｏｎ１１２膜和低铂载量Ｅ－ＴＥＫ电极组装的ＰＥＭＦＣ,在输出功率高达０．９５Ｗ／ｃｍ＾２;同时考察了电池的能量转换效率、Ｅ－ＴＥＫ电极中铂电催化剂利用率和电池的稳定性。     

生物质快速热解制备液体燃料

本文回顾了生物质快速热解液化技术的国内外研究现状,重点叙述了初级生物油的化学组成和燃料性质,指出生物油是一种复杂的含氧有机混合物,具有水分含量高、氧含量高、热值低、酸含量高、安定性差和化石燃油不互溶等独特的性质;针对这些性质,介绍了几种常用的生物油精制提炼方法,包括催化裂解、催化加氢、高温热解气过滤、添加助剂、催化酯化、柴油乳化以及制备富氢合成气与费托合成,并分析了各种精制技术发展的关键问题。     

直接甲醇燃料电池的稳定性

综述了近年来在直接甲醇燃料电池性能衰减方面的研究进展, 探讨了影响电池运行稳定性的主要因素.     

直接甲醇燃料电池高稳定性Pt/RuO_2/C阴极催化剂研究

应用湿化学法制备RuO2/C纳米复合物,并以其为载体借助微波法制备成Pt/RuO2/C催化剂.使用透射电镜和X射线衍射分析RuO2/C载体、Pt/RuO2/C催化剂的形貌及晶体结构;循环伏安、稳态阳极腐蚀和旋转圆盘电极等测试电化学性能.结果表明,Pt/RuO2/C催化剂具有良好的耐甲醇渗透性和稳定性,可有效延长催化剂的使用寿命.本文为探索新型高性能DMFC阴极催化剂之制备提供了一条较好的途径.