Catalyst Stability Benchmarking for the Oxygen Evolution Reaction: The Importance of Backing Electrode Material and Dissolution in Accelerated Aging Studies
Catalyst Stability Benchmarking for the Oxygen Evolution Reaction: The Importance of Backing Electrode Material and Dissolution in Accelerated Aging Studies
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DOI：
10.1002/cssc.201701523
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发表时间：
2017-11-09
期刊：
影响因子：
8.4
通讯作者：
Cherevko, Serhiy
中科院分区：
文献类型：
--
作者：
Geiger, Simon;Kasian, Olga;Cherevko, Serhiy
在寻找用于酸性水裂解的替代析氧反应（OER）催化剂时，在半电池测试中快速筛选材料固有活性和稳定性是至关重要的。筛选过程大大加快了新的有前途的材料的发现，而不需要耗时的真实细胞分析。在通常采用的测试中，关于催化剂稳定性的结论仅基于电化学数据得出，例如，通过评估电位-时间曲线。在本文中，证明了与背衬电极材料的降解相关的这种方法的重要局限性。研究了最先进的Ir-黑粉末的OER活性和作为背衬电极材料的函数的溶解。即使在非常短的时间间隔内，玻璃碳等材料也会钝化，增加接触电阻并掩盖电催化剂本身的降解现象。替代的背衬电极，如金和硼掺杂金刚石显示出更好的稳定性，因此建议用于短期加速老化研究。此外，电解质中的溶解产物的平行定量显示出对于比较OER催化剂的可行性是非常重要的。
In searching for alternative oxygen evolution reaction (OER) catalysts for acidic water splitting, fast screening of the material intrinsic activity and stability in half-cell tests is of vital importance. The screening process significantly accelerates the discovery of new promising materials without the need of time-consuming real-cell analysis. In commonly employed tests, a conclusion on the catalyst stability is drawn solely on the basis of electrochemical data, for example, by evaluating potential-versus-time profiles. Herein important limitations of such approaches, which are related to the degradation of the backing electrode material, are demonstrated. State-of-the-art Ir-black powder is investigated for OER activity and for dissolution as a function of the backing electrode material. Even at very short time intervals materials like glassy carbon passivate, increasing the contact resistance and concealing the degradation phenomena of the electrocatalyst itself. Alternative backing electrodes like gold and boron-doped diamond show better stability and are thus recommended for short accelerated aging investigations. Moreover, parallel quantification of dissolution products in the electrolyte is shown to be of great importance for comparing OER catalyst feasibility.