Direct Electrolytic Splitting of Seawater: Activity, Selectivity, Degradation, and Recovery Studied from the Molecular Catalyst Structure to the Electrolyzer Cell Level
Direct Electrolytic Splitting of Seawater: Activity, Selectivity, Degradation, and Recovery Studied from the Molecular Catalyst Structure to the Electrolyzer Cell Level
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DOI：
10.1002/aenm.201800338
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发表时间：
2018-08-06
影响因子：
27.8
通讯作者：
Strasser, Peter
中科院分区：
文献类型：
--
作者：
Dresp, Soeren;Dionigi, Fabio;Strasser, Peter
海水电解面临着基本的化学挑战，例如抑制高度有害的卤素化学物质，这必须通过选择性催化剂和合适的操作条件来确保。在本研究中，纳米结构的镍铁层状双氢氧化物和铂纳米粒子被选为阳极和阴极的催化剂，分别。在1.6 V、最大电流密度为200 mA cm（-2）的条件下，采用海水替代品对海水电解槽进行了100 h的成功测试，并与淡水进料进行了比较。进行不同的膜研究以揭示电流密度下降的原因。在长期动态测试中，在模拟昼夜循环下，发现了一种不寻常的电池功率性能恢复效果，随后在长期昼夜循环测试中进行了利用。当使用光伏电源时，电解槽输入功率的自然昼夜循环可以被认为是装置的可逆催化剂材料回收处理。为了理解这种可逆恢复的起源在分子材料水平上，在原位扩展的X射线吸收精细结构和X射线近边缘区光谱。
Seawater electrolysis faces fundamental chemical challenges, such as the suppression of highly detrimental halogen chemistries, which has to be ensured by selective catalyst and suitable operating conditions. In the present study, nanostructured NiFe-layered double hydroxide and Pt nanoparticles are selected as catalysts for the anode and cathode, respectively. The seawater electrolyzer is tested successfully for 100 h at maximum current densities of 200 mA cm(-2) at 1.6 V employing surrogate sea water and compared to fresh water feeds. Different membrane studies are carried out to reveal the cause of the current density drop. During long-term dynamic tests, under simulated day-night cycles, an unusual cell power performance recovery effect is uncovered, which is subsequently harnessed in a long-term diurnal day-night cycle test. The natural day-night cycles of the electrolyzer input power can be conceived as a reversible catalyst materials recovery treatment of the device when using photovoltaic electricity sources. To understand the origin of this reversible recovery on a molecular materials level, in situ extended X-ray absorption fine structure and X-ray near-edge region spectra are applied.