Hydrogen Production by Steam Electrolysis in Solid Acid Electrolysis Cells
Hydrogen Production by Steam Electrolysis in Solid Acid Electrolysis Cells
复制标题
DOI：
10.1002/cssc.202002281
复制
发表时间：
2020-11-17
期刊：
影响因子：
8.4
通讯作者：
Kikuchi, Ryuji
中科院分区：
文献类型：
--
作者：
Fujiwara, Naoya;Nagase, Hironori;Kikuchi, Ryuji
在中温下通过水蒸汽电解制氢具有高能量转换效率和适合于可再生能源利用的灵活可操作性的潜力。在200 ℃左右使用质子传导固体酸电解质被认为是有前途的，但很少被研究。这里，使用由CsH 2 PO 4/SiP 2 O 7复合电解质和Pt/C电极构成的固体酸电解池（SAEC）在160-220 ℃下进行蒸汽电解。氢气生产成功地证明了法拉第效率约为80%。首次详细考察了影响SAEC稳定性的关键因素。结果表明，在运行过程中，有一部分电解质迁移到多孔阳极结构中。迁移的电解质阻止气体扩散并淹没Pt/C催化剂层。研究还发现，阳极中的碳质材料被氧化，导致电化学活性位点的数量减少。基于这些发现，采用Pt网作为替代阳极。具有Pt网阳极的SAEC显示出上级稳定性，证明了阳极设计的重要性。目前的工作提供了一个全面的稳定性问题，这是必不可少的持久和实用的SAECs的发展。
Hydrogen production by steam electrolysis at intermediate temperatures has potential for both the high energy conversion efficiency and the flexible operability suitable for the utilization of renewable energy resources. Employment of proton-conducting solid acid electrolytes at around 200 degrees C is considered promising but has rarely been investigated. Here, steam electrolysis was performed at 160-220 degrees C using a solid acid electrolysis cell (SAEC) composed of a CsH2PO4/SiP2O7 composite electrolyte and Pt/C electrodes. Hydrogen production was successfully demonstrated with Faraday efficiencies around 80 %. Key factors affecting the SAEC stability were investigated in detail for the first time. It was revealed that a certain part of the electrolyte migrated into the porous anode structure during the operation. The migrated electrolyte prevented the gas diffusion and flooded the Pt/C catalyst layer. It was also found that carbonaceous materials in the anode was oxidized, leading to the decrease in the number of electrochemically active sites. Based on the findings, Pt mesh was employed as an alternative anode. The SAEC with the Pt mesh anode showed superior stability, demonstrating the importance of the anode design. The present work provides a comprehensive view of the stability issues, which is essential for the development of durable and practical SAECs.