Feasibility of an oxygen-getter with nickel electrodes in alkaline electrolysers
Abstract
Alkaline electrolysis is the long-established technology for water splitting to produce hydrogen and has been industrially used since the nineteenth century. The most common materials used for the electrodes are nickel and derivatives of nickel (e.g. Raney nickel). Nickel represents a cost-effective electrode material due to its low cost (compared to platinum group metals), good electrical conductivity and exhibits good resistance to corrosive solutions. The steady degradation of the nickel electrodes over time is known as a result of oxide layer formation on the electrode surface. Reducing oxide layer growth on the electrode surface will increase the efficiency and lifetime of the electrolyser. Titanium has a higher affinity to oxygen than nickel so has been introduced to the electrolyser as a sacrificial metal to reduce oxide layer formation on the nickel. Two identical electrolysers were tested with one difference: Cell B had titanium chips present in the electrolyte solution, whilst Cell A did not have titanium present. SEM results show a reduction of 16 % in the thickness of the Cell B oxide layer on nickel compared to the Cell A nickel, which is supported by the large increase in oxide layer build-up on the titanium in Cell B. EDX on the same samples showed on average a 59 % decrease in oxygen on the Cell B nickel compared to Cell A. XPS surface analysis of the same samples showed a 17 % decrease in the oxygen on Cell B nickel. These results support the hypothesis that adding titanium to an alkaline electrolyser system with nickel electrodes can reduce the oxide layer formation on the nickel.Citation
Feasibility of an oxygen-getter with nickel electrodes in alkaline electrolysers 2014, 3 (2) Materials for Renewable and Sustainable EnergyJournal
Materials for Renewable and Sustainable EnergyAdditional Links
http://link.springer.com/10.1007/s40243-014-0027-4Type
Journal articleLanguage
enISSN
2194-14592194-1467
ae974a485f413a2113503eed53cd6c53
10.1007/s40243-014-0027-4
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