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101.
《International Journal of Hydrogen Energy》2022,47(22):11633-11643
The effects of pore formers added into the extrusion slurry of anode support microtubes on the mechanical and electrochemical performance of the microtubes are investigated in this study. For this purpose, several microtubular anode supports are fabricated by using various pore formers with different particle sizes. The effect of pore former content is also taken into consideration for a certain pore former type. The flexural strengths of the anode support microtubes are measured via three point bending tests and reliability analysis is performed. The porosities of the anode supports are also determined along with microstructural investigations. The results reveal that the flexural strength decreases with increasing the particle size of the pore former employed for a fixed pore former content and with increasing the pore former content for a certain pore former material considered. In addition, a number microtubular cells are fabricated based on the various microtubular anode supports and their electrochemical performances are evaluated via performance and impedance tests. The impedance results indicate that the cell performance is mainly restricted by the diffusion polarization. Among the pore former materials considered in this study, the highest cell performance for a certain pore former content of 20 vol% is measured from the cell prepared with graphite (325 mesh) pore former at all temperatures and hydrogen flowrates studied. The optimization studies display that the cell performance can be further improved by increasing the pore former content to 22.5 vol% for this pore former material. 相似文献
102.
本工作采用一种简便的一步化学气相沉积(chemical vapor deposition, CVD)法,在泡沫镍基底上直接生长螺线形碳纳米纤维(CNFs/NF)作为对析氧反应有活性的整体式催化剂载体。在1 mol/L KOH为电解质溶液的三电极电解池中,与 CNFs/NF电极材料电化学表面积(ECSA)成正比的的双层电容Cdl值达到13.69 mF/cm2。通过循环伏安法,电化学阻抗谱和线性扫描伏安曲线等电化学手段,验证了CNFs/NF适于做具有析氧反应活性的催化剂载体。CNFs/NF需要260 mV,385 mV的析氧反应过电势以实现10 mA/cm2和100 mA/cm2的电流密度。 相似文献
103.
《International Journal of Hydrogen Energy》2022,47(58):24255-24267
This paper presents hydrogen generation measurements from the hydrolysis of NaBH4 aqueous solutions catalyzed by Co doping on single, bimetallic and trimetallic oxide supports (Co/CuO, Co/NiO, Co/Al2O3, Co/NiO–Al2O3, Co/CuO–Al2O3, and Co/CuO–NiO–Al2O3). Support materials are synthesized by the co-precipitation method. Then, Co is doped into support materials by the impregnation method. It is found that Co/CuO–NiO–Al2O3 catalyst exhibited high reaction activity with a maximum hydrogen generation rate (HGR) of 2067.2 ml min?1 gcat?1 at 25 °C. The effect of temperature of the solution, Co amount, and recyclability of the catalyst on hydrogen generation with Co/CuO–NiO–Al2O3 catalyst is investigated in detail. In addition, the highest HGR for Co/CuO–NiO–Al2O3 catalyst is obtained at 55 °C as 6460.0 ml min?1 gcat?1. The activation energy is calculated to be 31.59 kJ mol?1 using Co/CuO–NiO–Al2O3 catalyst. Co/CuO–NiO–Al2O3 catalyst exhibits zero-order reaction kinetics concerning NaBH4 concentration. In addition, the Co/CuO–NiO–Al2O3 catalyst provided high reusability after 5 cycles. 相似文献
104.
105.
从分析深井高应力大断面巷道和硐室破碎围岩的变形破坏特点入手,指出巷道稳定性的控制机理在于及时强化失稳区围岩的残余强度,阻止初次失稳的发展,并施加高强的主动支护结构,从而使巷道进入二次稳定状态,同时采取高强的被动封闭支护技术。提出了全断面双强壳体支护设计、3S耦合协调支护设计和抗张拉强基础梁支护设计等设计方案来控制巷道变形。并对绞车房进行现场施工,支护效果良好,达到预期目标。 相似文献
106.
该文分析了加强综采工作面超前支护的必要性,对传统的综采工作面超前支护技术存在的不足进行了分析;就如何加强新型综采工作面超前支护技术的应用进行了探讨。 相似文献
107.
《Journal of the European Ceramic Society》2014,34(2):373-379
Apatite-type lanthanum silicate based films have attracted significant interests to use as an electrolyte of solid oxide fuel cells (SOFCs) working at intermediate temperature. We have prepared Mg doped lanthanum silicate (MDLS) films on NiO–MDLS cermet substrates by spin coating and sintering of nano-sized printable paste made by beads milling. Changes in crystal structure and microstructure of the paste films with the sintering temperature have been investigated to show that porous network structure with a grain growth evolves up to 1300 °C, whereas densification occurred above 1400 °C. Anode supported SOFCs using the pasted MDLS films were successfully fabricated: an open circuit voltage of 0.91 V and a maximum power density of 150 mW cm−2 measured at 800 °C were obtained with the electrolyte film sintered at 1500 °C. 相似文献
108.
109.
文章介绍了茂金属催化剂载体的研究新进展,着重介绍了无机载体和有机载体用于茂金属催化剂负载化的研究现状。分别陈述了无机和有机载体的一些常见载体类型,例如硅胶载体和聚苯乙烯载体;并对比了无机载体和有机载体的颗粒形态,强度,表面基团等物理化学性质的差异。研究表明,载体材料本身结构及其物理化学性质对聚合活性,聚合物形态和堆积密度有着直接的作用。进一步探索载体的结构性能与聚合动力学的关系,将对对进一步提高聚合活性,改善聚合物颗粒形态具有深远的意义。 相似文献
110.
三角平衡轮廓轮胎是一种新型的轮胎结构,以低扁平率的传统轮廓轮胎255/30R22为基础,在其胎肩处和胎侧处增加高强度的支撑块来提高轮胎的性能。支撑块起到支撑胎面的作用,提高了胎侧的刚度。本文以滚动阻力计算公式和材料内耗机理为基础,用ABAQUS软件分别模拟2种轮胎的滚动阻力来验证三角平衡轮廓轮胎是否具有较低的滚动阻力。首先建立三角平衡轮廓轮胎和255/30R22轮胎的三维模型,施加相同载荷,对其进行以60km/h滚动工况的力学分析,算出单元积分点的生热率,提取每个单元的体积,最后计算每一种胶料的滚动阻力及轮胎总滚动阻力。通过两者的对比,三角平衡轮廓轮胎的滚动阻力仅18.7N,低于255/30R22轮胎滚动阻力的二分之一。 相似文献