TY - JOUR
T1 - Electro-osmotic flow and the limiting current in alkaline water electrolysis
AU - Haverkort, J. W.
AU - Rajaei, H.
PY - 2020
Y1 - 2020
N2 - Under alkaline conditions, hydroxide ions can deplete at the anode of a water electrolyser for hydrogen production, resulting in a limiting current density. We found experimentally that in a micro-porous separator, an electro-osmotic flow from anode to cathode lowers this limiting current density. Using the Nernst-Planck equation, a useful expression for the potential drop in the presence of diffusion, migration, and advection is derived. A quasi-stationary, one-dimensional model is used to successfully describe the transient dynamics. Electro-osmotic flow-driven cross-over of dissolved oxygen is argued to impact the hydrogen purity.
AB - Under alkaline conditions, hydroxide ions can deplete at the anode of a water electrolyser for hydrogen production, resulting in a limiting current density. We found experimentally that in a micro-porous separator, an electro-osmotic flow from anode to cathode lowers this limiting current density. Using the Nernst-Planck equation, a useful expression for the potential drop in the presence of diffusion, migration, and advection is derived. A quasi-stationary, one-dimensional model is used to successfully describe the transient dynamics. Electro-osmotic flow-driven cross-over of dissolved oxygen is argued to impact the hydrogen purity.
KW - Alkaline water electrolysis
KW - Hydrogen purity
KW - Limiting current density
KW - Microporous separator
UR - http://www.scopus.com/inward/record.url?scp=85095439483&partnerID=8YFLogxK
U2 - 10.1016/j.powera.2020.100034
DO - 10.1016/j.powera.2020.100034
M3 - Article
AN - SCOPUS:85095439483
SN - 2666-2485
VL - 6
JO - Journal of Power Sources Advances
JF - Journal of Power Sources Advances
M1 - 100034
ER -