Bi-Functional Iron-Only Electrodes for Efficient Water Splitting with Enhanced Stability through In Situ Electrochemical Regeneration
Bi-Functional Iron-Only Electrodes for Efficient Water Splitting with Enhanced Stability through In Situ Electrochemical Regeneration
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DOI：
10.1002/aenm.201502095
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发表时间：
2016-03-23
影响因子：
27.8
通讯作者：
Reisner, Erwin
中科院分区：
文献类型：
--
作者：
Martindale, Benjamin C. M.;Reisner, Erwin
作为生产负担得起的可再生氢气的一种全球适用手段，实施水分离技术需要可伸缩和坚固耐用的电催化剂。结果表明，在碱性电解液中，纯铁电极材料对质子还原和水氧化均具有良好的催化活性，其活性优于已有的元素丰度较低的双功能催化剂。已报道的铁电极的双功能是可逆的，只要通过电极表面催化物种的电化学相互转化来切换施加的偏压。循环施加的偏压导致催化剂表面的原位电化学再生，从而延长了催化剂的稳定性和水电解槽的寿命。在I=10 mA cm(-2)的电流密度下，在大约2V的偏压下实现了完全的水分裂，并且在至少3d(72个1小时的开关周期)中是稳定的。因此，在对称分水体系中，电位切换被确立为稳定电极材料以防止降解的一种可能策略。
Scalable and robust electrocatalysts are required for the implementation of water splitting technologies as a globally applicable means of producing affordable renewable hydrogen. It is demonstrated that iron-only electrode materials prove to be active for catalyzing both proton reduction and water oxidation in alkaline electrolyte solution with superior activity to that of previously established bi-functional catalysts containing less abundant elements. The reported bi-functionality of the iron electrodes is reversible upon switching of the applied bias through electrochemical interconversion of catalytic species at the electrode surface. Cycling of the applied bias results in in-situ electrochemical regeneration of the catalytic surfaces and thereby extends the catalyst stability and lifetime of the water electrolyzer. Full water splitting at a current density of I = 10 mA cm(-2) is achieved at a bias of approximate to 2 V, which is stable over at least 3 d (72 one hour switching cycles). Thus, potential-switching is established as a possible strategy of stabilizing electrode materials against degradation in symmetrical water splitting systems.