菜单
  

    Go to:
    Methods
    Fabrication of electrochemical cell for ammonia synthesis
    Nafion 211 membrane (DuPont®) was boiled in 3% H2O2 for 1 hour, rinsed by deionised water, boiled in de-ionised water for 2 hours then in 0.5 M H2SO4 for 1 hour. After rinsing with deionised water a few times, the membrane was stored in deionised water for cell fabrication.
    Pt/C (E-Tek, 30 wt%) on SGL gas diffusion layer (GDL 10 BC) was used as both electrodes with a Pt loading of 1 mg cm−2. Some 5% Nafion suspension (Aldrich) and isopropanol were mixed with Pt/C catalysts for preparation of the catalytic layer. The membrane electrode assembly (MEA) with a working area of 1 cm2 was fabricated by hot pressing.
    The MEA was put in electrochemical cell testing jig using graphite as bipolar plates. 35 wt% ammonia aqueous solution (Alfa Aesar) was pumped to both sides of the cell by a parasitic pump (Waterson Marlon 320) for one day to convert H+-form Nafion 211 membrane into NH4+-form. De-ionised water was then pumped to the cell for one week to clean up the residual ammonia and no ammonia can be detected from the outlets. A d.c. voltage of 40 mV was applied to the cell for 4 hours to activate the MEA and improve the electrode/electrolyte interfaces then air was flowed through both cathode and anode chambers overnight before ammonia synthesis experiments. All the presented experimental data were collected from the same MEA.
    Ammonia synthesis and detection
    H2 (or water) and N2 (or air) were passed through room temperature water first then filled into the chambers of the cell. The dc potential was applied by a Solartron 1470A electrochemical interface controlled by software Cell Test® for automatic data collection. The order for applied voltage was from low to high. The produced ammonia was collected by dilute H2SO4 (0.001 M). The concentration of  in the absorbed solution was analysed using Nessler's reagent (Aldrich). The produced ammonia was detected using an ammonia meter (Palintest 1000) and the rate of ammonia formation was calculated using the following equation.
     
    Where [NH4+] is the measured NH4+ ion concentration, V is the volume of the dilute H2SO4 for ammonia collection, t is the adsorption time and A is the effective area of the cell.
    Go to:
    Author Contributions
    S.W.T. and R.L. drafted and J.T.S.I. revised the manuscript. S.W.T. and J.T.S.I. conceptualized the study. R.L. and S.W.T. performed synthesis, characterization and analysis.
    Go to:
    Supplementary Material
    Supplementary Information:
    Supplementary information
    Click here to view.(26K, pdf)
    Go to:
    Acknowledgments
    This work was funded by EPSRC SuperGen ‘Delivery of Sustainable Hydrogen' project (EP/G01244X/1).
    Go to:
    References
    1.    Lan R., Irvine J. T. S. & Tao S. W.Ammonia and related chemicals as potential indirect hydrogen storage materials. Inter. J. Hydrogen Energy37, 1482–1494 (2012).
    2.    Bastidas D. M., Tao S. W. & Irvine J. T. S.A symmetrical solid oxide fuel cell demonstrating redox stable perovskite electrodes. J. Mater. Chem.16, 1603–1605 (2006).
    3.    Pool J., Lobkovsky E. & Chirik P.Hydrogenation and cleavage of dinitrogen to ammonia with a zirconium complex. Nature427, 527–530 (2004). [PubMed]
    4.    Amar I. A., Lan R., Petit C. T. G. & Tao S. W.Solid-state electrochemical synthesis of ammonia: a review. J. Solid State Electrochem.15, 1845–1860 (2011).
    5.    Waugh K. C., Butler D. & Hayden B. E.The mechanism of the poisoning of ammonia-synthesis catalysts by oxygenates O2, CO and H2O - An in-situ method for active surface determination. Catal. Lett.24, 197–210 (1994).
    6.    Jennings J.Catalytic ammonia synthesis: fundamentals and practice. (Springer, 1991).
    7.    Chatt J., Pearman A. & Richards R.The reduction of mono-coordinated molecular nitrogen to ammonia in a protic environment. Nature253, 39–40 (1975).
  1. 上一篇:基于政府视角的安全生产标准化推进措施与建议
  2. 下一篇:企业员工竞业禁止研究+文献综述
  1. 中英文图书标签的比较研究

  2. 静态开发模式理论视角下...

  3. 工艺美术产业宜兴紫砂壶...

  4. CS工厂工艺安全分析及优化研究

  5. 英文论文沙特企业员工激励管理研究

  6. 汉工坊软陶工艺品创意设...

  7. 乳业同业并购式全产业链...

  8. 杂拟谷盗体内共生菌沃尔...

  9. 中考体育项目与体育教学合理结合的研究

  10. 河岸冲刷和泥沙淤积的监测国内外研究现状

  11. 十二层带中心支撑钢结构...

  12. 大众媒体对公共政策制定的影响

  13. 当代大学生慈善意识研究+文献综述

  14. 电站锅炉暖风器设计任务书

  15. java+mysql车辆管理系统的设计+源代码

  16. 酸性水汽提装置总汽提塔设计+CAD图纸

  

About

751论文网手机版...

主页:http://www.751com.cn

关闭返回