fig2
Figure 2. Mass transfer processes: (A) in the Pt-based cathode catalyst layer of PEMFCs; (B) in the Ir-based anode catalyst layer of PEMWEs. SL: Support layer; MPL: microporous layer; PTL: porous transport layer; PEM: proton exchange membrane; PEMFC: PEM fuel cell; PEMWE: PEM water electrolyzer.
