Mass transport in PEM water electrolysers: A review

Anion Exchange Membrane Water Electrolyzer: Electrode Design, Lab-Scaled Testing System and Performance Evaluation

“…R 3 indicates the mass transfer limit, which is the small semicircle at the low frequency of the Nyquist plot. The mass transport issue is mainly subject to water/gas management dominated by the GDL structure [241]. A lack of efficient water delivery to the MEA and delayed removal of the generated gas will not only contribute to an uplifted mass transfer resistance but also entails high contact resistance and active site blockage, which in turn will add to the ohmic and charge transfer resistance, thus negatively damaging the cell performance [202].…”

The porous transport layer in proton exchange membrane water electrolysis: perspectives on a complex component

“…Under typical industrial operating conditions the mass transport overpotential accounts for up to 25% of the total overpotential of a PEMWE. 8 For an indepth understanding, mass transport aspects, including mass transport in the liquid-gas diffusion layer, has been reviewed and discussed in PEMWE by Maier et al 81 Electrical conduction. Conductivity, the inverse of resistivity, is frequently measured to quantify the electrical conduction of materials.…”

Nucleation as a rate-determining step in catalytic gas generation reactions from liquid phase systems

“…The relevance of bubble nucleation for the rate of relevant multiphase processes has been recognized for a couple of technically relevant applications but, so far, not for classical heterogeneous catalysis. In contrast, the gas evolution rate of different electrochemical processes, including hydrogen production in water electrolysis ( 8 , 9 ), gas evolution in aluminum electrolysis ( 10 ), and CO 2 formation in direct methanol fuel cells ( 11 ), has been related to the systems’ ability to nucleate product gas bubbles. Moreover, it has been found that structured surfaces enhancing heterogeneous nucleation provide positive rate effects on the oxygen evolution from hydrogen peroxide ( 12 ) and on boiling processes in heat exchange devices ( 13 , 14 ).…”