Space-averaged mass transport measurements are reported for a planar, 1 dm(2) Pt/Ti cathode in a divided filterpress reactor, using the reduction of 0.05 M K3Fe(CN)(6) in a solution also containing 0.05 M K4Fe(CN)(6) and 1 M KOH at 298 K. In the case of the empty channel, mass transport coefficient (k(m)) values ranged from 2.3 x 10(-6) to 2.7 x 10(-5) m s(-1) over the volumetric flow rate range of 0.1 to 4.2 x 10(-4) m(3) s(-1). The use of eight different polymer mesh turbulence promoters resulted in mass transport enhancement factors of 1.05 to 2.20 compared to the empty channel data at the same flow rate. Examination of the structure of the promoters allowed the mass transport enhancement factor to be related to a geometrical function of the promoters. Mass transport in this reactor is compared with that in other laboratory and pilot scale cells using Sherwood number vs. Reynolds number correlations.