Analysis of mass transport processes in the anodic porous transport layer in PEM water electrolysers

In this contribution, the transport processes in the anodic porous transport layer (A-PTL) in proton exchange membrane (PEM) water electrolysis are studied in detail. A spatially distributed model of the transport processes in the A-PTL is derived and implemented, which is able to predict stationary saturation profiles and to detect drying-out behaviour at the anodic catalyst layer. The influence of the material properties on the transport limitations is analysed in order to avoid a drying-out of the system. The analysis showed that a suitable PTL material should have a porosity of epsilon(0) > 0.6, a permeability of, and a contact angle of theta < 45 degrees. It is also shown that a sufficiently high water saturation in the channel of is crucial for the transport behaviour. Additionally, the bulk material properties of a Ti sintered fibre PTL are determined experimentally (epsilon(0) = 0.75, k(0) = 6.4 x 10(-14)m(2), theta = 30 degrees). (C) 2019 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.