Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7721166 | International Journal of Hydrogen Energy | 2013 | 10 Pages |
Abstract
In this study, we experimentally investigate the appearance of a local negative differential resistance (N-NDR) branch in polarization curves of a segmented 7 by 7 cell measured under the steady and highly-dynamic conditions. Under both conditions, a comma shaped polarization curve, corresponding to depletion of oxygen, was followed by an increase in current as the cell voltage was lowered. This characteristic was measured under potentiostatic mode, where no current is forced through the cell, and at a positive cell voltage (<100Â mV in steady-state and â¼300Â mV in dynamic condition). With a theoretical model, we show that at these positive cell voltages and upon the depletion of oxygen, a shift in the Nernst potential occurs allowing for the hydrogen evolution reaction to take place in the cathode catalyst layer. The results of the model are complemented with experimental measurements of produced hydrogen at the cathode outlet.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Nada Zamel, Richard Hanke-Rauschenbach, Sebastian Kirsch, Arjun Bhattarai, Dietmar Gerteisen,