A simple convertible electrolyzer in membraneless and membrane-based modes for understanding water splitting mechanism

JOURNAL OF POWER SOURCES

卷:487

Article

Yang, Gaoqiang¹  Yu, Shule¹  Li, Yifan¹  Li, Kui¹  Ding, Lei¹  Xie, Zhiqiang¹  Wang, Weitian¹  Dohrmann, Yeshiemebet¹  Zhang, Feng-Yuan¹ 

[1] Univ Tennessee, Dept Mech Aerosp & Biomed Engn, UT Space Inst, Knoxville, TN 37996 USA

关键词: Membraneless;    Convertible electrolyzer;    In-situ visualization;    Coplanar electrodes;    Water splitting;    Oxygen evolution reaction (OER);    Hydrogen evolution reaction (HER);   

DOI  :  10.1016/j.jpowsour.2020.229353

来源: Elsevier

【 摘 要 】

State-of-the-art membrane-based electrolyzers such as proton exchange membrane electrolyzer cells, are costly, susceptible to degradation, and time-consuming for electrode evaluation and triple-phase boundary electrochemical reaction studies. Here, a simple convertible electrolyzer in membraneless and membrane-based modes is proposed. For the first time, this enables comprehensive investigations of water splitting with pure water, acidic and alkaline electrolytes in one cell. With the simple electrolyzer and high-speed visualization system, the influences of flow rate, electrolytes, concentration, and Nafion membrane on the oxygen evolution reactions (OERs), hydrogen evolution reactions (HERs) and electrolyzer performance are comprehensively investigated. Visualization results reveal that water splitting only occurred at the edge between the electrode and the Nafion membrane in pure water. However, they occurred on the whole electrode surface in alkaline and acidic electrolytes, indicating easily tunable reaction sites with the convertible electrolyzer. This demonstrates the feasibility of using the simple convertible electrolyzer for understanding the water splitting mechanism. The relation between electrolyte thickness and resistances with different electrolytes is also quantified. This work provides an insight for optimizing electrochemical devices while delivering an inexpensive and fast way for electrode evaluations and electrochemical reaction studies.

【 授权许可】

Free