Electrochemical investigation of novel reference electrode Ni/Ni(OH)2 in comparison with silver and platinum inert quasi-reference electrodes for electrolysis in eutectic molten hydroxide
Electrochemical investigation of novel reference electrode Ni/Ni(OH)2 in comparison with silver and platinum inert quasi-reference electrodes for electrolysis in eutectic molten hydroxide
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DOI：
10.1016/j.ijhydene.2019.08.248
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发表时间：
2019-10-18
影响因子：
7.2
通讯作者：
Chen, George Z.
中科院分区：
文献类型：
--
作者：
Al-Shara, Nawar K.;Sher, Farooq;Chen, George Z.
高效、绿色的水裂解制氢技术已成为满足清洁、可持续能源需求的重要研究领域。在这项研究中，通过共晶熔融氢氧化物（NaOH-KOH; 49-51摩尔%）电解裂解蒸汽生产氢气已经在250-300 ℃下进行了电化学研究。使用了三种类型的参比电极，例如高温莫来石膜Ni/Ni（OH）（2）、准银和准铂型。该电极研究的主要目的是在熔融氢氧化物电解质中找到合适的、稳定的、可再现的和可重复使用的参比电极。采用循环伏安法研究了在不同扫描速率和熔盐温度下控制工作电极对反应动力学和稳定性的影响。还研究了通过Ar气流向共晶熔融氢氧化物中引入水的效果。当电位扫描速率在50 ~ 150 mV·s（-1）范围内变化时，铂丝工作电极的还原电流与新制备的镍参比电极无明显变化，表明其具有稳定性和重现性。此外，将熔融氢氧化物的操作温度从250 ° C增加到300 ° C，所制备的镍参比电极的还原电位略微正移约0.02V。这表明其具有良好的温度稳定性。所制备的镍和Pt参比电极表现出稳定和可靠的循环伏安法结果与和不存在的低共熔熔融氢氧化物中的蒸汽，而银参比电极暴露的还原电位的正移高达0.1 V。与其它准参比电极相比，所设计的参比电极对铂工作电极具有更稳定和有效的控制性能。因此，通过熔融氢氧化物分解蒸汽以获得氢气已经显示出当前制氢技术的有希望的替代方案，该制氢技术可用于热和发电。(C)2019年氢能出版有限责任公司。由爱思唯尔有限公司出版。保留所有权利。
An efficient and green energy carrier hydrogen (H-2) generation via water splitting reaction has become a major area of focus to meet the demand of clean and sustainable energy sources. In this research, the splitting steam via eutectic molten hydroxide (NaOH-KOH; 49-51 mol%) electrolysis for hydrogen gas production has been electrochemically investigated at 250-300 degrees C. Three types of reference electrodes such as a high-temperature mullite membrane Ni/Ni(OH)(2), quasi-silver and quasi-platinum types were used. The primary purpose of this electrode investigation was to find a suitable, stable, reproducible and reusable reference electrode in a molten hydroxide electrolyte. Cyclic voltammetry was performed to examine the effect on reaction kinetics and stability to control the working electrode at different scan rate and molten salt temperature. The effect of introducing water to the eutectic molten hydroxide via the Ar gas stream was also investigated. When the potential scan rate was changed from 50 to 150 mV s(-1), the reduction current for the platinum wire working electrode was not changed with newly prepared nickel reference electrode that designates its stability and reproducibility. Furthermore, increasing the operating temperature of molten hydroxides from 250 to 300 degrees C the reduction potential of the prepared nickel reference electrode is slightly positive shifted about 0.02 V. This suggests that it has good stability with temperature variations. The prepared nickel and Pt reference electrode exhibited stable and reliable cyclic voltammetry results with and without the presence of steam in the eutectic molten hydroxide while Ag reference electrode exposed positive shifts of up to 0.1 V in the reduction potential. The designed reference electrode had a more stable and effective performance towards controlling the platinum working electrode as compared to the other quasi-reference electrodes. Consequently, splitting steam via molten hydroxides for hydrogen has shown a promising alternative to current technology for hydrogen production that can be used for thermal and electricity generation. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.