The jet aerator as oxygen supplier for the electrochemical generation of H2O2

Abstract

The hydrogen peroxide is a key and versatile compound that can be readily produced in one-pot electrochemical reactors via the 2 e− oxygen reduction reaction. In all the electrolyzers studied up to date, the external aeration is carried out by means of a compressor. In this work, the compressor is substituted by a device based on the Venturi effect to minimize the acquisition, maintenance and operating costs associated to the aeration of the reactor. Interestingly, it was found that this aerator can super saturate in oxygen the solution thanks to the formation of air bubbles. The catalytic effect of carbon black (CB) and/or polytetrafluoroethylene (PTFE) to increase the production of H2O2 was studied, observing a synergistic effect when the CB/PTFE mixture was deposited on the carbon felt cathode. Efficient hydrogen peroxide generation was obtained at 15mAcm−2: instantaneous production rate of around 9.2mg H2O2 h−1cm−2 and a corresponding current efficiency in the order of 90%. The limiting current density increased when the jet aerator was used thanks to i) the super saturation of the solution (dissolved oxygen+air bubbles) and ii) the ability of the CB/PTFE modified carbon felt to use them as oxygen source. The jet aerator is rather promising for the electrochemical generation of hydrogen peroxide.