Development of high-performance silver-based gas-diffusion electrodes for chlor-alkali electrolysis with oxygen depolarized cathodes
Development of high-performance silver-based gas-diffusion electrodes for chlor-alkali electrolysis with oxygen depolarized cathodes
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DOI：
10.1016/j.cep.2011.11.003
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发表时间：
2012-02-01
影响因子：
4.3
通讯作者：
Turek, Thomas
中科院分区：
文献类型：
--
作者：
Moussallem, Imad;Pinnow, Stefan;Turek, Thomas
制备了银基气体扩散电极，并对电极进行了表征和测试。将含有银催化剂颗粒、PTFE悬浮液、表面活性剂和有机增稠剂的水性悬浮液喷涂在镍网上，然后干燥、热压和烧结，可以制备高活性电极。系统地研究了由最合适的催化剂SF 9 ED（Ferro）获得的电极。最好的电极含有97-98重量%银和2-3重量%聚四氟乙烯，是热压在约。130摄氏度，并随后在约340摄氏度的温度下烧结。对于这些电极，半电池电位约。650 mV vs. RHE，对应于电解槽电压约为在电流密度为4kA/m ~ 2时，获得了2.17V的电压。发现半电池和电解电池电压在使用来自不同批次的电极的重复测量期间在约+/-30mV内是可再现的。虽然Ag/PTFE负载量对所研究范围（100-300 mg/cm（2））内观察到的电压几乎没有影响，但建议负载量至少为200 mg/cm（2），以防止NaOH电解液泄漏，并允许在超过100 mbar的氧气过压下操作，而不会使气体突破电解液。(C)2011 Elsevier B. V.保留所有权利。
Silver-based gas-diffusion electrodes were prepared, characterized and tested during chlor-alkali electrolysis with oxygen depolarized cathodes. Spraying of aqueous suspensions containing silver catalyst particles, a PTFE suspension, a surfactant and an organic thickening agent on nickel nets followed by drying, hot-pressing and sintering allowed for the preparation of highly active electrodes. Electrodes obtained from the most suitable catalyst SF9ED (Ferro) were systematically investigated. The best electrodes contain 97-98 wt.% silver and 2-3 wt.% PTFE, are hot-pressed at ca. 130 degrees C with moderate pressure and subsequently sintered at temperatures around 340 degrees C. For these electrodes, half cell potentials of ca. 650 mV vs. RHE corresponding to electrolysis cell voltages of ca. 2.17V at current densities of 4 kA/m(2) were obtained. Both half cell and electrolysis cell voltages were found to be reproducible within about +/- 30 mV during repeated measurements using electrodes from different batches. While the Ag/PTFE loading had little influence on the observed voltages in the range studied (100-300 mg/cm(2)), loadings of at least 200 mg/cm(2) are recommended to prevent leakage of NaOH electrolyte and to allow for operation under oxygen overpressures of more than 100 mbar without breakthrough of gas to the electrolyte. (C) 2011 Elsevier B.V. All rights reserved.