Electrochemical generation of ozone in a membrane electrode assembly cell with convective flow

Abstract

Highly efficient electrochemical generation of ozone on doped tin dioxide anodes was reported recently. Here, we report the scale up of such ozone generation on a membrane electrode assembly (MEA) made with 8×13 cm -doped tin dioxide anode. The effects of water flow rate, operating voltage, and current on dissolved ozone concentration, ozone production, current efficiency, and energy efficiency are reported. Ozone production and current efficiency increased with water flow. Operating with a single MEA, 218 mgh of dissolved ozone was produced at an applied current of 6 A (current density=57.6 mA cm2). With four MEAs operated in a stack, the dissolved ozone production increased to 1.1 gh at a total current of 20.6 A (current density=49.5 mA cm2) and individual cell voltage of 3.3 V. For the multiple MEA operation, the highest current efficiency was 21.7% based alone on dissolved ozone generation. The lowest energy consumption achieved was 42 kWhkg (O3) at 643 mg ozone per hour at current of 10.1 A (current density=24.3 mA cm2) and water flow of 5.4 Lmin (linear velocity=7.03 cms). © 2009 The Electrochemical Society.