Dry reforming of methane powered by magnetic induction

Dry reforming of methane is a highly endothermic reaction that produces syngas from CH₄ and CO₂. It operates at 800–1000 °C to meet thermodynamic constraints, achieve high equilibrium conversion and minimize catalyst deactivation due to carbon deposition. In this paper we report our experimental results on the catalytic activation of dry reforming powered by induction heating. Energy is supplied by a radiofrequency alternating magnetic field to Ni₆₀Co₄₀ alloy that works at the same time as catalyst for the reforming reaction and heat generator by dissipation of the electromagnetic energy. In such a way, the heat of reaction is directly provided by the catalytic bed, avoiding dissipation due to inefficient transfer from outside the reactor.Temperatures higher than 850 °C have been easily reached using Ni₆₀Co₄₀ pellets as heat mediators in a continuous-flow fixed-bed reactor. At this temperature methane conversion and hydrogen production occurred with yield comparable to those obtained by conventional heating. Reported evidences open new opportunities in the research of magnetic materials for industrial chemical processes.     

高频脉冲电镀镍钴合金拉伸强度的研究

研究了高频脉冲电镀Ni-Co复合镀层的拉伸力学性能、显微硬度及镀层表面的微观形貌。结果表明,随着频率的增加,沉积层表面更加致密、均匀,显微硬度增大,镀层的弹性模量及拉伸强度随脉冲频率增加而先增大后减小,并在80 kHz处取得最大值。     

国内外镍钴产品标准与质量现状及综述

对当前国内外镍钴产品标准及质量的现状进行综述 ,介绍了电解镍、钴及氧化钴的标准修订情况。     

镍钴合金电沉积中硫酸钴影响的探讨

电沉积镍层硬度低,耐磨性差,在瓦特型镀镍液中加入硫酸钴可以提高镀层的抗热性能、耐蚀性能和韧性.采用硫酸盐电解液电沉积镍钴合金,研究了电解液中硫酸钴浓度与镀液分散能力、深镀能力的关系及其对镀层显微硬度、孔隙率和内应力的影响.同时,利用扫描电子显微镜分析了沉积层的表面形貌.结果表明:随着镀液中硫酸钴浓度的增大,镀液的分散能力下降,深镀能力升高;镀层显微硬度显著提高,内应力和孔隙率也有所增加.镍钴合金沉积层比纯镍镀层更细致、结晶均匀.     

Ni-Co/WC-Graphite复合熔覆层的组织与三点弯曲行为

采用真空熔覆技术制备了Ni-Co/WC-Graphite(G)复合熔覆层,采用SEM、XRD等分析了微观组织及相组成,利用三点弯曲研究了复合熔覆层的弯曲行为,并分析了断口形貌特征、微区元素分析与断裂机制。结果表明:整个Ni-Co/WC-G熔覆层包括复合层区、过渡层区、扩散冶金熔合带以及热影响扩散区,复合层区呈现三维织构组织特征,主要组成相有Cr_7C_3、Cr_(23)C_6、Ni_3Si、CrB、WC、C和γ-Ni-Co固溶体,扩散影响区主要组织为珠光体,扩散冶金熔合带及过渡层主要组成相为镍钴基合金固溶体及金属间化合物;具有复合熔覆层试样的三点弯曲载荷-位移曲线初始呈线性变化,而后曲线斜率逐渐减小,在达到载荷峰值时Ni-Co/WC-G复合熔覆层在承受压应力时溃裂,而在承受拉应力时断裂,由于过渡层、扩散冶金带以及热影响扩散区的存在,使载荷在熔覆层失效后仍在一定范围内缓慢增加,熔覆层区断口形貌呈沿晶或穿晶特征,基体侧的热影响扩散区呈扇形解理断裂特征,远离界面的基体区域为具有大量韧窝的韧性断裂。     

Ni-Co/Ti催化剂制备及其对葡萄糖的电催化氧化

采用水热法制备了一种新型多孔镍钴修饰钛电极(Ni-Co/Ti)。利用循环伏安、电位阶跃等电化学技术研究了碱性溶液中Ni-Co/Ti电极对葡萄糖氧化的电催化活性。双电位阶跃分析表明,葡萄糖在该体系中的扩散系数为6.50×10-6cm2/s,葡萄糖在Ni-Co/Ti电极电化学氧化反应速率常数为3.57×104cm3/(mol.s)。实验表明,Ni-Co/Ti电极对葡萄糖氧化具有优异的电催化活性。     

P507-Cyanex272协同萃取分离回收废旧镍氢电池中镍钴金属新工艺研究

在废镍氢电池浸出液除杂的基础上,采用P507-Cyanex272协同萃取分离回收浸出液中的有价金属镍钴,通过实验找出适合的工艺条件,使工艺简化,成本降低。     

硫酸高铈改善Ni-Co合金电镀层性能的机理

为了改进Ni-Co合金镀层的性能,在Ni-Co合金镀液中添加不同含量的Ce(SO4)2.4H2O,研究了其对Ni-Co合金镀层及镀液性能的综合影响,获得了Ce(SO4)2.4H2O最佳添加量及Ni-Co合金镀的最佳工艺参数。结果表明:镀液中Ce(SO4)2.4H2O的添加范围是0.56～1.12g/L,添加量为1.00g/L时,镀液的沉积速度、分散能力及镀层外观质量都到达最佳,镀层厚度也比较大;但Ce(SO4)2.4H2O会降低镀液的覆盖能力。     

On work function and characteristics of anomalous electrodeposited nickel-cobalt films

The anomalous cobalt content in the electrodeposited nickel-cobalt (Ni-Co) alloy films significantly influenced by the current density was related to the variation of morphology and electron work function (EWF) of the films. The characteristics and EWF of Ni-Co films were investigated by scanning electron microscope with an attached energy dispersive X-ray spectrometer, X-ray diffraction, ultraviolet photoelectron spectroscopy (UPS) and Kelvin probe technique, respectively. As the current density increased from 1 to 20 ampere per square decimeter (A/dm²), the Co atomic concentration (at.%) in Ni-Co greatly decreased from 22.5 at.% to 13.2 at.% correspondingly. The surface morphology of film obtained at low current density became smoother than that at high current density. Both UPS and Kelvin probe results showed the same trend of EWF variation which increased with increasing current density from 1 to 10 A/dm² and kept nearly unchanged at 10-20 A/dm². The smooth Ni-Co film with low EWF could be achieved at low current density. In comparison, Kelvin probe operated at atmosphere ambient could be a good candidate for EWF measurement because of the lower cost and easier operation than UPS at ultra high vacuum.     

Electrodeposition and morphology of Ni, Co and Ni-Co alloy powders: Part II. Ammonium chloride supporting electrolyte

Polarization characteristics of the processes of Ni and Co powders and Ni-Co alloy powders electrodeposition from ammonium chloride containing supporting electrolyte and their morphologies are investigated as a function of Ni²⁺ and Co²⁺ ions concentrations. It is found that the shape of the polarization curves in all cases is practically defined by the shape of the polarization curve for hydrogen evolution. It is shown that correct polarization curves, as well as the morphology of electrodeposited powders are sensitive to the ratio of Ni²⁺/Co²⁺ ions concentration. Characteristic feature of powder particles obtained from chloride containing electrolytes is the presence of cone-shaped cavities. In the case of Ni powder cauliflower and spongy type particles are detected, while Co powder contains only spongy type particles. In all cases of alloy powder formation anomalous type of co-deposition is detected.