Water electrolysis under microgravity - Part 1. Experimental technique
Water electrolysis under microgravity - Part 1. Experimental technique
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DOI：
10.1016/s0013-4686(03)00579-6
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发表时间：
2003-12-15
影响因子：
6.6
通讯作者：
Kuribayashi, K
中科院分区：
文献类型：
--
作者：
Matsushima, H;Nishida, T;Kuribayashi, K
在碱性（25重量%）和碱性（25重量%）中进行水电解。KOH，2重量% KOH）和酸（0.1 N H2SO 4）溶液中进行8 s的处理。用CCD摄像机观察了氢气和氧气在铂电极上形成气泡的过程。在碱性溶液中，电极表面生长气泡泡沫层。氢气泡的尺寸小于氧气泡的尺寸。恒电位下的电流密度随时间的延长而不断减小。尽管在电极上的气泡泡沫层的生长，电解从未停止，显然是因为新鲜的电解质被供应到电极表面由气泡演变引起的微对流。在酸性溶液中，氢气泡经常聚结在阴极表面上，产生比氧气更大的平均气泡。与可逆氢电极（RHE）相比，在-0.4 V至-0.8 V的恒定电位下，电流密度没有变化，因为与碱性电解质相比，更大的气泡尺寸显着降低了有效电极表面积。目前的实验表明，特别是在微重力环境中，气泡的演化行为和所得的电流-电位曲线显着影响的电极与电解质接触的润湿性。(C)2003 Elsevier Ltd.保留所有权利。
Water electrolysis was conducted in both alkaline (25 wt.% KOH, 2 wt.% KOH) and acid (0.1 N H2SO4) solutions for 8 s under microgravity environment realized in a drop shaft. The gas bubble formation of hydrogen and oxygen on platinum electrodes was observed by CCD camera. In alkaline solutions, a bubble froth layer grew on the electrode surface. Hydrogen bubble size was smaller than that of oxygen. The current density at constant potential decreased continually with time. In spite of the growth of a bubble froth layer on the electrode, the electrolysis never stopped, apparently because fresh electrolyte is supplied to the electrode surface by microconvection induced by the gas bubble evolution. In acid solution, hydrogen gas bubbles frequently coalesced on the cathode surface, yielding a larger average bubble than that of oxygen. The current density did not vary at constant potentials from -0.4 to -0.8 V versus reversible hydrogen electrode (RHE), because the effective electrode surface area was significantly reduced by the larger bubble size compared to alkaline electrolyte. The present experiments indicate that, especially in a microgravity environment, the bubble evolution behavior and the resultant current-potential curves are significantly influenced by the wettability of the electrode in contact with the electrolyte. (C) 2003 Elsevier Ltd. All rights reserved.