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1.
The present work addresses the potentialities of Pt–Ru nanoparticles deposited on a graphene oxide (RGO) and TiO2 composite support towards electrochemical oxidation of ethanol in acidic media relevant for fuel cell applications. To immobilize platinum–ruthenium bimetallic nanoparticles on to an RGO-TiO2 nanohybrid support a simple solution-phase chemical reduction method is utilized. An examination using electron microscopy and energy dispersive X-ray spectroscopy (EDS) indicated that Pt–Ru particles of 4–8 nm in diameter are dispersed on RGO-TiO2 composite support. The corresponding Pt–Ru/RGO-TiO2 nanocomposite electrocatalyst was studied for the electrochemical oxidation of ethanol in acidic media. Compared to the commercial Pt–Ru/C and Pt/C catalysts, Pt–Ru/RGO-TiO2 nanocomposite yields higher mass-specific activity of about 1.4 and 3.2 times, respectively towards ethanol oxidation reaction (EOR). The synergistic boosting provided by RGO-TiO2 composite support and Pt–Ru ensemble together contributed to the observed higher EOR activity and stability to Pt–Ru/RGO-TiO2 nanocomposite compared with other in-house synthesized Pt–Ru/RGO, Pt/RGO and commercial Pt–Ru/C and Pt/C electrocatalysts. Further optimization of RGO-TiO2 composite support provides opportunity to deposit many other types of metallic nanoparticles onto it for fuel cell electrocatalysis applications.  相似文献   
2.
The ohmic resistance in solid oxide fuel cells (SOFCs) mainly comes from the electrolyte, which can be reduced by developing novel electrolyte materials with higher ionic conductivity and/or fabricating thin-film electrolytes. Among various kinds of thin-film fabrication technology, the physical vapor deposition (PVD) method can reduce the electrolyte thickness to a few micrometers and mitigate the issues associated with high-temperature sintering, which is necessary for wet ceramic methods. This review summarizes recent development progress in thin-film electrolytes fabricated by the PVD method, especially pulsed laser deposition (PLD) and magnetron sputtering. At first, the importance of the substrate surface morphology for the quality of the film is emphasized. After that, the fabrication of thin-film doped-zirconia and doped-ceria electrolytes is presented, then we provide a brief summary of the works on other types of electrolytes prepared by PVD. Finally, we have come to the summary and made perspectives.  相似文献   
3.
This study assesses a sustainable solution to greenhouse gases (GHGs) mitigation using constructed wetland-microbial fuel cells (CW-MFC). Roots of wetland plant Acorus Calamus L. are placed in biological anode to better enable anode microorganisms to obtain rhizosphere secretion for power improvement. Three selected cathode materials have a large difference in GHG emissions, and among them, carbon fiber felt (CFF) shows the lowest emissions of methane and nitrous oxide, which are 0.77 ± 0.04 mg/(m2·h) and 130.78 ± 13.08 μg/(m2·h), respectively. The CFF CW-MFC achieves the maximum power density of 2.99 W/m3. As the influent pH value is adjusted from acidic to alkaline, the GHGs emissions are reduced. The addition of Ni inhibits GHGs emission but decreases the electricity, the power density is reduced to 1.09 W/m3, and the methane and nitrous oxide emission fluxes decline to 0.20 ± 0.04 mg/(m2·h) and 15.49 ± 1.86 μg/(m2·h), respectively. Low C/N ratio reduces methane emission, while high C/N ratio effectively inhibits nitrous oxide emission. At the influent pH 8 and C/N = 5:1, the methane emission flux is approximately 10.60 ± 0.27 mg/(m2·h), and the nitrous oxide emission flux is only 10.90 ± 1.10 μg/(m2·h). Based on the above experimental results by controlling variable factors, it is proposed that CW-MFC offers an environment-friendly solution to regulate GHG emissions.  相似文献   
4.
超临界机组高温合金管氧化膜剥落问题是困扰机组安全与经济运行的难题,严重制约了机组蒸汽参数和效率的提高。特别是,在超临界机组采用给水加氧处理方式(OT)后,奥氏体不锈钢管内壁氧化膜大面积剥落事故屡见不鲜,尤以TP347H合金管为甚。本文总结了近年来国内外针对超临界机组合金管氧化膜研究的进展及相关成果,首先介绍了超临界蒸汽环境中合金管氧化机理和原子迁移机制,综述了铁素体和奥氏体合金表面氧化膜的形貌特征,分析了蒸汽溶氧对氧化膜生长速率、形貌和缺陷的影响。氧化膜完整性是决定合金抗腐蚀性能的重要因素,但在机组运行过程中氧化膜应力破坏了氧化膜完整性。进一步总结了国内外氧化膜应力和剥落研究的数值分析及实验研究情况,为我国超临界机组氧化膜剥落故障诊断研究提供参考。  相似文献   
5.
针对某铅锌尾矿嵌布粒度细、氧化程度高、泥化严重的问题,进行了一系列浮选试验研究.采用硫化混合浮选的工艺流程,经过一粗五精三扫浮选,在磨矿细度-0.074 mm含量占95%条件下,选取最优参数进行闭路实验,最终获得铅品位15.05%、回收率为34.31%,锌品位39.23%、回收率为49.82%的铅锌混合精矿.  相似文献   
6.
采用酸浸法从新疆紫金低品位氧化锌矿及含锌废石制备碱式碳酸锌。在磨矿细度为-74μm占30%,液固比2,硫酸用量52kg/t矿,浸出时间2h,终点pH 1.5~2.0,锌浸出率为63%,氧化锌浸出率97%左右;浸出液采用碳酸钙预中和—碳酸钠沉锌工艺回收锌,在预中和终点pH 4.5~5.0、碳酸钠沉锌终点pH 8.0左右,最终获得锌沉淀率为99%,锌品位约50%的碱式碳酸锌产品,该产品可作为生产电锌的原料。  相似文献   
7.
层状氧化物正极材料具有良好的结构稳定性和较高的充放电比容量,是一类理想的钠离子电池正极材料。本工作研究了层状氧化物正极材料NaNi1/3Fe1/3Mn1/3O2表面修饰对其电化学性能的影响,采用固相球磨法在正极材料表面包覆一层纳米ZrO2,采用形貌、结构、电化学方法等研究了包覆后性能改进机理。研究结果表明,ZrO2在NaNi1/3Fe1/3Mn1/3O2表面形成一层惰性保护层,有效隔开了电解液与正极材料的接触,缓解了电解液的分解速度,抑制了金属离子的溶出速度,从而显著改善了电池的循环性能以及高温性能。在ZrO2包覆修饰后,55℃下正极材料相比于未包覆的正极材料有明显提升,100次循环后容量保持率达到83.6%,高于未包覆的75.2%。此外,包覆后的NaNi1/3Fe1/3Mn1/3O2正极材料在空气环境存储后,稳定性得到明显提高。  相似文献   
8.
针对国内外锌冶炼行业技术发展现状,以北矿机电科技有限责任公司研制的新一代大极板自动剥锌机组为研究对象,首先介绍了大极板自动剥锌机组基本结构与工作流程,然后对阴极板自动装卸机构进行结构设计和工作过程分析,解决了进口剥锌机需要人工辅助钩板的弊端,实现了阴极板自动装卸彻底无人化操作,大幅提高了剥锌效率和设备的安全性可靠性,具有重要的工程应用指导意义。  相似文献   
9.
BaCe0.7Zr0.1Y0.2O3-δ (BCZY) is one of the promising electrolytic candidate for solid oxide fuel cell (SOFC) due to its good proton conductivity and better stability. Herein, the effect of dual sintering aids such as CuO-Bi2O3 upon the sinterability at low temperature, improved electrochemical properties, and thermo-chemical changes about proton-conducting BaCe0.7Zr0.1Y0.2O3-δ electrolyte were investigated in detail. FESEM micrographs and shrinkage curves revealed significant improvement in sinterability and densifications of BCZY electrolyte. The dense pellets were sintered with CuO-Bi2O3 (2–3 mol %) as sintering aids at a temperature of 1150 °C for 5 h. The perfectly uniform distribution of sintering aids increased the linear shrinkage of BCZY from 5% till 19–21%. The crystallite size and grain growth within the structure was enhanced due to the formation of the melting phase of Bi2O3 and Cu2+ incorporation in the perovskite structure. The elevated and improved electrochemical measurement for BCZY with 2 mol% of CuO-Bi2O3 as sintering aid categorized it well suited for solid oxide fuel cells.  相似文献   
10.
The introduction of catalyst on anode of solid oxide fuel cell (SOFC) has been an effective way to alleviate the carbon deposition when utilizing biogas as the fuel. A series of La0.6Sr0.4Co1-xNixO3-δ (x = 0, 0.2, 0.4, 0.6, 0.8) oxides are synthesized by sol-gel method and used as catalysts precursors for biogas dry reforming. The phase structure of La0.6Sr0.4Co1-xNixO3-δ oxides before and after reduction are characterized by X-ray diffraction (XRD). The texture properties, carbon deposition, CH4 and CO2 conversion rate of La0.6Sr0.4Co1-xNixO3-δ catalysts are evaluated and compared. The peak power density of 739 mW cm?2 is obtained by a commercial SOFC with La0.6Sr0.4Co0.4Ni0.6O3-δ catalyst at 850 °C when using a mixture of CH4: CO2 = 2:1 as fuel. This shows a great improvement from the cell without catalyst for internal dry reforming, which is attributed to the formation of NiCo alloy active species after reduction in H2 atmosphere. The results indicate the benefits of inhibiting the carbon deposition on Ni-based anode through introducing the La0.6Sr0.4Co0.4Ni0.6O3-δ catalyst precursor. Additionally, the dry reforming technology will also help to convert part of the exhaust heat into chemical energy and improve the efficiency of SOFC system with biogas fuel.  相似文献   
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