Fig. 2: Effects of fluid field.

a, b Schematic illustrations of MEA-SR (a) and MEA-FR (b). c, d 2D distribution of the computed velocity components in the effective mass transfer direction across the electrode cross-section using MEA-SR (c) and MEA-FR (d). e, f NO3− concentration distribution within the porous electrode in MEA-SR (e) and MEA-FR (f). g, h Shear force distribution on cross-sectional plane of the porous electrode in MEA-SR (g) and MEA-FR (h).