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Electrochemical synthesis of hydrogen peroxide with a three‐dimensional rotating cylinder electrode
Author(s) -
González Pérez Omar,
Bisang José M.
Publication year - 2014
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.4149
Subject(s) - electrolysis , electrode , electrochemistry , cylinder , current (fluid) , analytical chemistry (journal) , materials science , hydrogen peroxide , current density , rotational speed , glassy carbon , carbon fibers , hydrogen , oxygen , chemistry , composite material , chromatography , thermodynamics , cyclic voltammetry , organic chemistry , mechanical engineering , physics , quantum mechanics , composite number , engineering , electrolyte
BACKGROUND This work analyzes the synthesis of H 2 O 2 from dilute NaOH solutions under 0.1 MPa O 2 using a batch reactor with a three‐dimensional rotating cylinder electrode. The centrifugal force produces a radial co‐current flow of the gas and liquid phases. Thus, good mass transfer conditions are achieved and the O 2 reduced to H 2 O 2 is easily replenished in the liquid phase.RESULTS Experiments with a glassy carbon rotating disc electrode identified 0.5 mol L ‐1 NaOH at 30°C as suitable operating conditions. Galvanostatic experiments with three‐dimensional rotating electrodes concluded that the best performance was obtained for a reticulated vitreous carbon structure of 100 ppi, at 40 mA cm ‐2 of macrokinetic current density and 1000 rpm rotation speed. Long‐term experiments showed 79% current efficiency and 8.2 kWh kg ‐1 specific energy consumption until 6 h of electrolysis, with 8.4 g L ‐1 H 2 O 2 concentration. However, the current efficiency decreases for longer electrolysis times and consequently the specific energy consumption is increased. Thus after 10 h electrolysis the concentrations were H 2 O 2 10.4 g L ‐1 and NaOH 1.41 mol L ‐1 .CONCLUSION A reactor having a three‐dimensional rotating cylinder electrode with co‐current oxygen and liquid flows inside the structure showed promising performance for H 2 O 2 production. © 2013 Society of Chemical Industry