共查询到18条相似文献,搜索用时 234 毫秒
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在纳米晶Co—Mo/Ni复合电极上的析氢反应 总被引:3,自引:0,他引:3
采用复合电镀的方法将不同球磨时间制备的高催化活性的纳米晶Co-Mo合金粉直接镀在电极表面,用稳态极化曲线及交流阻抗技术测试了这些电极析氢的电化学活性,并用X射线衍射,透射电镜及X射线光电子能谱,扫描电镜监测了Co-Mo合金粉的物相结构,晶粒尺寸和复合镀的成份,形貌,实验结果表明,Co-Mo纳米晶合金粉有较高的析氢催化活性,球磨使钴钼粉合金化成为纳米晶,一方面增加了复合镀层的真实表面积,另一方面由于 相似文献
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Ni—Mo合金复合镀层上的析氢反应 总被引:6,自引:1,他引:6
用稳态极化曲线及交流阻抗等电化学技术研究了不同沉积条件(沉积温度、沉积时间、沉积电流、镀液组成)所得纳米晶Ni-Mo合金复合镀层上的析氢反应,并用扫描电镜及X光能谱监测了电极表面的形貌及镀层组成,实验结果表明:沉积温度30℃、沉积7200s,较大的沉积电流及含钼镀液对析氢更为有利 相似文献
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Ni—WC复合电极的结晶结构及其电化学性能的研究 总被引:2,自引:0,他引:2
本文在优选的工艺条件下制备了Ni-WC复合电极。其SEM观察和XRD测试结果表明:复合电极中的Ni是以比Ni电极的Ni更微小的晶粒存在。复合电沉积过程中,导电性的WC微粒的存在,对基质金属Ni的电沉积方式产生了影响,使基质金属Ni几乎无择优取向性。采用循环伏安法对其电化学性能进行研究,实验结果表明:Ni-WC复合电极在碱性水溶液析氢反应中与H质子之间的吸附作用及吸附量高于Ni电极,对硝基苯的电还原反应具有比Ni电极更良好的催化活性。 相似文献
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机械合金化Mg/MmNi5-x(CoAlMn)x复合储氢合金的组织结构与吸氢特性 总被引:6,自引:0,他引:6
运用X射线衍射、扫描电及粒度分析等方法表征了机械合金化制备Mg/MnNi5-x(CoAlMn)x复合储氢合金的结构,通过PCT曲线研究了基储氢性能。结果表明,在适当的球磨条件下能够获得纳米晶结构的Mg/MnNi5-x(CoAlMn)x复合储氢合金,MmNi5-x(CoAlMn)x合金相彘,复合储氢合金的活化性能及储氢量有明显提高。此外,还考察了Mg含量对复合储氢合金的组织结构及储氢性能的影响。 相似文献
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制备了一系列不同配比的Fe-Mo氧化物催化剂,采用比表面积,XRD,FT-IR和LRS等方法,考察了催化剂的有关物化性质,测定了对甲苯选择性氧化生成苯甲醛的催化活性。用TPD-MS技术研究了催化剂表面氧物种的脱附。结果表明,随着样品中Fe/Mo含量的改变,表面氧物种的脱附峰的峰温,氧脱附量和脱附活化能Ed也发生变化。3#样品的氧脱附峰峰温较低,表面氧物种O^-和O^2-脱附量最大,Ed值最小,生成 相似文献
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采用电沉积法获得Ni、Ni-Fe和Ni-Fe-C合金镀层电极, 在90 °C模拟海水(0.5 mol·L-1 NaCl, pH=12)的稳态极化曲线表明Ni-Fe-C合金电极具有最好的析氢催化性能. 通过扫描电子显微镜(SEM)观察电极表面形貌、X射线衍射(XRD)与透射电子显微镜(HRTEM)分析合金的晶体结构, 发现电极材料的晶粒尺寸影响析氢催化性能, 晶粒尺寸越小析氢催化活性越好. 用电化学阻抗方法(EIS)研究电极析氢催化性能的本质原因, 结果表明电极表面活性点数目和电极的本质电催化活性对合金电极析氢催化活性有重要的影响. 相似文献
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Ni-Co-LaNi5复合电极材料在碱性介质中的电催化析氢性能 总被引:4,自引:0,他引:4
电催化析氢反应是电能向化学能转化的一个有效途径,是电化学科学中一个非常值得深入研究的课题。阴极析氢超电势的降低,是提高析氢活性,降低电解能耗的关键。为了提高电极的电催化活性,一是可通过提高电极表面的真实表面积,来降低电解过程中电极表面的真实电流密度,达到降低析氢超电势的目的;另一发展方向是提高电极材料本身的电化学活性,即寻找高催化活性的新型析氢材料犤1犦。由于过渡金属具有特殊的d电于结构,是目前公认的电化学活性最好的电极材料,而在过渡金属中,Ni及Ni合金将是研究的主要方向,其中多元合金复合材料将成为该技术发展… 相似文献
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Florentina Golgovici Alexandru Pumnea Aurora Petica Adrian Cristian Manea Oana Brincoveanu Marius Enachescu Liana Anicai 《Chemical Papers》2018,72(8):1889-1903
In the case of hydrogen production involving seawater electrolysis, one of the main targets is to develop more active cathodic materials, to optimize the efficiency of hydrogen evolution reaction (HER) and, by doing so, enhance the overall energy efficiency of electrolysis. Thus, to develop suitable HER electrocatalysts either an increase of the electrode active surface area or a design of a material having high intrinsic catalytic activity should be taken into consideration, both of them decreasing the HER overpotential. In the present work, various Ni–Mo alloy nanostructures (10–40 wt% Mo) have been prepared involving electrochemical deposition from aqueous and deep eutectic solvent (DES)-based electrolytes as potential cathodic materials suitable for hydrogen evolution reaction during water electrolysis. The electrocatalytic activity of the obtained layers has been investigated using real seawater electrolyte. The determined Tafel slopes suggested that the electrodeposited Ni–Mo alloy coatings follow an HER mechanism controlled by the Volmer reaction step. The EIS results indicated that the use of choline chloride-based ionic liquids as electrolytes facilitated Ni–Mo alloy coatings showing a significant increase in surface roughness. Studies of the intrinsic activity showed that the main contribution towards the apparent activity comes from the increase of the real surface area, although a slight increase of the intrinsic electrocatalytic activity in the case of Ni–Mo alloy coatings electrodeposited on Ni foam was also noticed. These results showed that Ni–Mo alloy coatings electrodeposited from the novel electrolytes based on choline chloride–urea–citric acid ternary mixtures associated with a porous substrate may represent a promising technological approach to build cathodic materials suitable for seawater electrolysis. 相似文献
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Electroless and electroplated nickel electrodes are extensively used for hydrogen evolution reaction (HER). In the present
work, TiO2-supported IrO2 mixed oxide composite was prepared and used to reinforce Ni–P electroless plates to be used as catalytic electrodes for HER.
The electrodes exhibited high electrocatalytic activity when the electrodes were used for HER. All the parameters including
particle size of the catalyst, surface roughness, and surface active sites were studied. The particle size of the IrO2 catalyst in the mixed oxide was found to have high influence on the catalytic activity of the electrodes. Low overpotential
as low as 70 mV at a current density of 200 mA cm−2 was achieved with the mixed oxide-reinforced Ni–P electrodes. 相似文献
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Development of cathode material which has low HER (hydrogen evolution reaction) overpotential and high durability is significant to electrolysis industry and antifouling with electrolyzing seawater. The amorphous Ni-S alloy electrode was prepared by means of electrodeposition. Its electrocatalytic activity and stability for HER in 5 mol/L NaOH solution at 353 K was investigated. The result showed that the amorphous Ni-S alloy in which sulphur content is 29.4%, has high electrocatalytic activity and excellent stability. In addition, the morphology and phase structure of the NiSx alloy electrode before and after electrolysis were studied by SEM (scanning electron microscope) and XRD (X-ray diffraction). 相似文献
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《Journal of Energy Chemistry》2015,(5)
Replacing platinum for catalyzing hydrogen evolution reaction(HER) in acidic medium remains great challenges. Herein, we prepared few-layered Mo S2 by ball milling as an efficient catalyst for HER in acidic medium. The activity of as-prepared Mo S2 had a strong dependence on the ball milling time. Furthermore,Ketjen Black EC 300 J was added into the ball-milled Mo S2 followed by a second ball milling, and the resultant Mo S2/carbon black hybrid material showed a much higher HER activity than Mo S2 and carbon black alone.The enhanced activity of the Mo S2/carbon black hybrid material was attributed to the increased abundance of catalytic edge sites of Mo S2 and excellent electrical coupling to the underlying carbon network. 相似文献