Electrocatalytic oxygen evolution on nickel oxy-hydroxide anodes: Improvement through rejuvenation
By Sophia R. Mellsop and Alister Gardiner and Aaron T. Marshall
Published in Electrochimica Acta
NULL
2015
Abstract
The ageing and rejuvenation behaviour of nickel oxy-hydroxide anodes for alkaline water electrolysis is investigated. The anodically formed oxy-hydroxide material is known to age over time causing a decrease in performance. However, this deactivation can be mitigated by temporarily reducing the potential for brief periods. This work looks at continuous rejuvenation of nickel anodes in 30 wt.% \KOH\ solution and it is shown that rejuvenation at 0.5 V vs. HgHgO for 10 minutes every 100 minutes can prevent ageing of the anode, thus maintaining a low overpotential during galvanostatic oxygen evolution at 50 mA cm?2. It is suggested that the short potentiostatic rejuvenation periods at regular intervals prevents the ratio of Ni(IV) to Ni(III) from increasing, thereby maintaining the intrinsic activity of the material. The rejuvenation potential must be above 0.36 V vs. HgHgO to ensure it is effective in obtaining good performance (i.e. the material must not reduce to Ni(II)). These findings suggest that electrolysis systems using nickel anodes could benefit from direct coupling to fluctuating power sources such as solar or wind, where the variability in their power output could facilitate the rejuvenation of the nickel anode. We estimate that by using the rejuvenation steps, an energy saving of 9% is possible in an alkaline water electrolyser using nickel anodes.
Microsoft is Ending Support for Windows 7
Microsoft will discontinue support for Windows 7 on January 14, 2020 which means Gamry will also be discontinuing support for Windows 7. If you are upgrading to Windows 10, like many companies and institutions, you need to be running Version 7 of our s oftware . Please note that only USB and Ethernet-based instruments can run in Version 7. Eligible users can download the latest version of our software through our online Client Portal .
If you haven't already registered your instrument, you can do so through the Client Portal .
Please email Technical Support if you have any questions regarding this transition. Please be sure to include your instrument model and serial number when contacting us.