An experimental comparison of a graphite electrode and a gas diffusion electrode for the cathodic production of hydrogen peroxide

Abstract

This work studies the production of hydrogen peroxide through the cathodic reduction of oxygen in acidic medium, by comparing the results obtained using a commercial graphite and a gas diffusion electrode. A low pH was required to allow the application of hydrogen peroxide generation to an electro-Fenton process. The influence of applied potential and the gas flow composition were investigated. The gas diffusion electrode demonstrates a higher selectivity for hydrogen peroxide production, without significantly compromising the iron regeneration, thus making its successful application to a cathodic Fenton-like treatment, possible. Unlike the graphite cathode, the gas diffusion cathode also proved to be effective in the air flow

Mathematical Modeling in Chemical Engineering: A Tool to Analyse Complex Systems

“…Fig.9 shows the results with reference to simulated values obtained from CSTR model. A good match between simulated and experimental values is observed at the beginning of electrolysis, in accordance with the literature (Da Pozzo et al, 2005). At longer times, the model overestimates hydrogen peroxide production, perhaps due to several factors, e.g., higher rate of side reactions (15) and (16) (Da Pozzo et al, 2005), electrode flooding (Pasaogullari & Wang, 2004), or existence of considerable local overpotential or OHconcentration values on the cathode surface, followed by H 2 O 2 decomposition and H 2 O production (Alcaide et al, 2002;Agladze et al, 2007;Kolyagin & Kornienko, 2003), not represented by the first-order kinetic equation used in this first model approach.…”

“…Due to the low solubility of the oxygen in aqueous solution, in the electrosynthesis of hydrogen peroxide, electrochemical devices with high specific surface area are required. Gas-diffusion electrodes (GDE) are devices suitable to supply commercially reasonable current densities for practical implementation of this process (Alcaide et al, 2002;Da Pozzo et al, 2005;Lobyntseva et al, 2007). The availability of mathematical models for optimal design and process control strategy, can improve the use of these devices.…”

Electrogeneration of hydrogen peroxide in seawater and application to disinfection

“…The cathode, of surface area about 5 cm 2 , was a carbon ''Vulcan'' gas diffusion electrode supplied by De Nora Tecnologie Elettrochimiche, fed with pure O 2 ; a platinum wire and a saturated calomel electrode (SCE) were respectively used as anode and reference electrode. The apparatus was described previously [27]. Where not differently indicated, electrolysis was conducted at the controlled potential of -0.9 V vs SCE, the catholyte consisted of 100 ml of synthetic seawater prepared from a certified mix of salt, and the anolyte was a 100 ml solution of sodium perchlorate 0.01 M. No supporting electrolyte was added to the catholyte, since conductivity was guaranteed by the salinity of seawater.…”

“…•-and hydroperoxide radicals HOO • , can be described by reaction 1: gas diffusion electrode, instead of the traditional graphite cathode, has resulted in increased production efficiency and decreased cost [27].…”

Anodic, cathodic and combined treatments for the electrochemical oxidation of an effluent from the flame retardant industry

“…A gas diffusion electrode has been used as the cathode for the in situ generation of hydrogen peroxide [18][19] via electrochemical reduction of oxygen (Eq. 2).…”