Glassy carbon tubular electrodes for the reduction of oxygen to hydrogen peroxide

Abstract

The oxygen reduction reaction (ORR) to produce hydrogen peroxide (H₂O₂) is of great industrial interest. Herein, a hydrodynamic electrochemical method is explored for use as a continuous method to produce H₂O₂ at the point-of-use. The ORR was studied in a tubular glassy carbon flow cell under a laminar flow regime. A generalised theoretical model was developed to explore the conditions, such as volume flow rates and tubular lengths etc., for which a near-full electrolysis may be achieved. The parameters probed, transfer coefficient, half-wave potentials, volume flow rates, etc., provide physical insights into the irreversible oxygen reduction process. Thereafter, the surface modification of the tubular electrode with an electrocatalyst, 2-anthraquinonyl group (AQ-), is investigated for the mediated reduction of oxygen. This is shown to usefully decrease the required overpotential for the reduction process.