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叙述M1Ni4.5Al0.5贮氢合金分离氢中氪、氙的基本原理,分了分离时氢中氪、浓度与分离温度的关系。结果表明,当T为298K时,贮氢合金N1Ni4.5Al0.5与TiFe0.86Mn0.1的分离性能基本相似,分离浓度与放氢体积符合N=ae^-br方程。 相似文献
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在22-60℃范围内研究了贮氢合金MnNi3.55Co0.75Mn0.44Al0.3(Mn为富铈混合稀土金属)在a和α+β相区恒温吸氢动力学过程。研究结果表明,合金在α相区吸氢受化学反应控速,动力学规律不受氢初压的影响,在整个α+β相区吸氢过程中,受氢在合金氢物中的扩散控速,得到相应的速率方程和表观活化能。 相似文献
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研究了富镧混合稀土贮氢合金MlNi5 及加Sn 后对合金的结构、活化性能、吸氢容量和平衡氢压等性能的影响。通过X 射线衍射分析进行物相分析, 测试了298 ,313,333 K 温度下合金的吸、放氢PCT曲线。结果表明,MlNi5 - xSnx 合金(x=0 ~0.4) 为六方晶体结构的单相组织。以Sn 部分取代Ni 改善了MlNi5 的活化特性, 并使平台压力降低, 吸、放氢滞后减小。随着Sn 含量增加, 晶胞体积增大, 平衡氢压降低, 生成热减小, 氢化物稳定性提高。而少量的Sn 对吸氢能力降低较小, 是理想的替代元素。 相似文献
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研究了富镧混合稀土贮氢合金MINi5及加Sn后对合金的结构、活化性能、吸氢容量和平衡氢压等性能的影响。通过X射线衍射分析进行物相分析,测试了298,313,333K温度下合金的吸、放氢P-C-T曲线。结果表明,MINi5-xSnx合金(x=0~0.4)为六言晶体结构的单相组织。以Sn部分取代Ni改善了MINi5的活化特性,并使平台压力降低、吸、放氢滞后减小。随着Sn含量增加,晶胞体积增大,平衡氢压 相似文献
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汽车氢化物空调机用贮氢合金的研究 总被引:1,自引:0,他引:1
针对汽车发动机尾气废热为驱动热源的应用要求,研究了一对新的稀土系贮氢合金对La0.6Ml0.4Ni4.7Cr0.8-La0.2Mm0.8Ni4.35Fe0.65。该合金对在150~250℃/35~45℃/15~20℃工作温度下做制冷循环时,最大工作氢容量为4.5H/molM,理论特性系数COPc为0.74,可基本满足氢化物空调机应用要求。 相似文献
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CO2在Cu-Ni/ZrO2-SiO2催化剂上的吸附与反应 总被引:12,自引:3,他引:9
采用表面反应改性法,制备了ZrO2-SiO2(ZrSiO)表面复合物,用等体积浸渍法制备了ZrSiO担载的Cu-Ni双金属催化剂,用IR和TPD技术,研究了CO2在其表面上的化学吸附与反应性能。实验结果表明:在Cu-Ni/ZrSiO催化剂CO2可形成线式吸附态、剪式吸附态和卧式吸附态;催化剂表面金属位M上的剪式吸附态CO2可与邻近的lewis酸位Zr^n+作用,形成CO2卧式吸附态M-(CO)- 相似文献
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Yu. I. Bauman I. V. Mishakov R. A. Buyanov A. A. Vedyagin A. M. Volodin 《Kinetics and Catalysis》2011,52(4):547-554
The formation of nanocarbon materials on massive nickel, nichrome, and some other alloys via the carbide cycle mechanism is
reported using 1,2-dichloroethane decomposition as an example. The role of the physical stage of the carbide cycle is elucidated,
and massive metal surface activation methods ensuring the realization of this stage are considered. The surface layer of massive
nickel or some nickel alloys is most effectively activated by the action of chlorine resulting from the catalytic decomposition
of 1,2-dichloroethane. It has been demonstrated by ferromagnetic resonance (FMR) spectroscopy that the activation of the massive
metal surface in 1,2-dichloroethane decomposition to nanocarbon is due to the surface undergoing crystal chemical restructuring.
The microstructuring of the surface yields fine Ni particles similar in size (0.2–0.3 μm) and shape, whose FMR spectra are
anisotropic and have similar magnetic resonance parameters. Both chlorine-free and chlorinated hydrocarbons decompose over
these particles via the carbide cycle mechanism. It is demonstrated that it is possible to design catalytic reactors packed
with massive nickel or its alloy. The nanocarbon material obtained in such a reactor will not be contaminated by components
of conventional catalyst supports (Al, Mg, etc.). The stable performance temperature of the catalyst will be increased, and
this will allow the equilibrium outlet methane concentration to be reduced. 相似文献
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In the previous paper, it was reported that a sudden decrease down to -0.6V and lower in stationary potential was observed from the stationary potential-time curve and the reaction of electroless nickeling could be induced by metallic iron catalyst when it was in contact with substrate metallic copper. In this paper, AES and XPS surface analysis and depth profile technique was employed to investigate the surface and depth distribution of Ni, Cu, Fe and P in the nickel coating deposited on the substrate metal. The experimental results showed that there was a thin adsorption layer consisting of C, S and Cl. The pure electroless nickel deposition, its Ni/P ratio being about two, existed under the adsorption layer. A layer with rapidly changed Ni/P ratio occurred close to the surface of substrate metal, under this layer the substrate metal was alloyed with Ni and P, thus becoming Cu-Ni-P alloy. The ratio of components in this alloy was found to be Cu:Ni:P=56:36:5. This fact explained why the electroless nickel deposition can preferably adhered to the substrate metal. In inducing process, Fe was not detected by AES from the substrate metal and nickel deposition. Thus it showed that the inducing reaction takes place without the deposition of inducing metal. 相似文献
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Cathodic hydrogen evolution on polycrystalline nickel with differently prepared surfaces and on individual faces of single-crystal nickel is studied. It is established that the hydrogen overvoltage on nickel in acid media considerably depends on the surface preparation technique. In some cases, the difference in the hydrogen overvoltage cannot be explained by different roughness of electrodes. The absorption of atomic hydrogen in a surface layer may substantially alter electrocatalytic properties of both polycrystalline and single-crystal nickel. 相似文献
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Performance evaluation of nickel as anode catalyst for DMFC in acidic alkaline medium 《燃料化学学报》2018,46(5):592-599
Direct methanol fuel cell (DMFC) research is highly focused due to its high energy density, portability and inexpensive. In the present study conventional platinum catalyst used for methanol oxidation is being replaced with nickel catalyst supported over nickel mesh. The electrode is synthesized by single step electro deposition technique. Synthesized electrode was characterized by SEM, EDAX and AFM techniques to know the surface morphology, composition and thickness of the catalyst respectively. The electro catalytic behavior of the nickel for methanol oxidation was evaluated using cyclic voltammetry technique. As the DMFC is compatible with both the acidic and alkaline electrolytes the working of the nickel mesh electrode is analyzed in both media. The results showed maximum current density of 0.025 and 0.030 A/cm2 in alkaline and acidic medium respectively with less potential around 0.4 and 0.2 V. The other parameters such as varying the concentration of methanol, electrolyte medium, scan rate and thickness of the catalytic layer were analyzed and optimized. 相似文献
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The oxidation and enhanced detection of traditionally 'non-electroactive' amino acids at a single-wall carbon nanotube (SWNT) surface and at a nickel hydroxide film electrochemically deposited and generated upon the SWNT layer is reported. Different CNT are compared, with Nafion-dispersed SWNT offering the most favorable layer for constant-potential amperometric detection. Factors affecting the oxidation process, including the pH or applied potential, are assessed. The response of the SWNT-Nafion coated electrode compares favorably with that of copper and nickel disk electrodes under flow injection analysis (FIA) conditions. The electrodeposition of nickel onto the SWNT-Nafion layer (Ni-CNT) led to a dramatic enhancement of the analytical response (vs. that observed at the SWNT or nickel electrodes alone). The oxidative process at the Ni(OH)(2) layer has been studied and the increase in sensitivity rationalized. In the presence of amino acid the Ni-CNT layer undergoes an electrocatalytic process in which the amino acid reduces the newly formed NiO(OH) species. Furthermore, the attractive response of both the CNT and Ni-CNT layers has allowed these electrodes to be used for constant-potential FIA of various amino acids and indicates great promise for monitoring chromatographic effluents. Once again an improved signal was observed at the Ni-CNT electrode compared to nickel deposited upon a bare glassy carbon electrode (Ni-GC). 相似文献
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锂离子二次电池碳负极材料的改性 总被引:5,自引:1,他引:5
作为锂离子二次电池的碳负极材料,其改性方面的研究内容主要有:引入非金属元素,引入金属元素,处理表面及其它方面。纺入的非金属元素有硼,硅,氮,磷和硫。引入的金属元素有钾,铝,镓和钒,镍,钴,铜,铁等过渡金属元素。表面处理的方法包括氧化,形成表面层等。 相似文献
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Ni(OH)2与NiOOH间相互转化的波长扫描椭圆偏振光谱分析研究 总被引:4,自引:0,他引:4
用波长扫描现场椭圆偏振光谱方法研究了镍电极上的电化学反应。vop光波以及拟合椭圆偏振实验数据证明,镍电极表面膜可用单层有效介质膜模型描述;椭圆偏振光谱法可用于表于表面分析。 相似文献
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Extraction of nickel in strongly acidic solution (0.01 approximately 8M hydrochloric acid) with ammonium 1-pyrrolidinecarbodithioate (APCD) into di-isobutyl ketone (DIBK) has been studied, and the APCD/DIBK system has been applied to simultaneous extraction and flame atomic-absorption spectrometric determination of trace amounts of copper and nickel in titanium metal. Nickel could be extracted with copper from strongly acidic solution such as up to 5M hydrochloric acid with APCD/DIBK system. The extraction from such a strongly acidic media made it possible to extract nickel with copper, since it did not require the addition of a large amount of the masking agent which prevents the hydrolysis of the matrix titanium and also prevents the extraction of nickel. Thus, they could be extracted directly from the titanium metal sample digested by concentrated hydrochloric acid with a small amount of tetrafluorohydroboric acid. Effect of coexistence of a large amount (at least 0.2 g) of iron on the extraction of both elements could be prevented by keeping most of the matrix titanium as Ti(III). With the method described here, mug/g levels of copper and nickel in titanium metal could be rapidly determined with good precision and accuracy. 相似文献