Electrosynthesis of hydrogen peroxide by partial reduction of oxygen in alkaline media. Part II: Wall-jet ring disc electrode for electroreduction of dissolved oxygen on graphite and glassy carbon
ABSTRACT A wall-jet ring disc electrode was constructed by adapting a wall-jet flow through electrochemical cell. Commercially available spectral graphite and glassy carbon were used as working disc electrodes and the ring electrode was made of stainless steel. The efficiency and rate constants, measured in a planar parallel flow hydrodynamic regime, indicated the partial electroreduction of dissolved oxygen as a quasi-reversible two-electron process for both electrode materials tested.
SourceAvailable from: Edgar J Ruiz-Ruiz[Show abstract] [Hide abstract]
ABSTRACT: Sodium percarbonate (SPC) can be produced electrochemically from aqueous Na(2)CO(3) solution in both its 2Na(2)CO(3)center dot 3H(2)O(2) and Na(2)C(2)O(6) forms simultaneously. This was achieved in a two-compartment cell separated by a cation-exchange membrane. Na(2)C(2)O(6) was produced on the anodic side by water oxidation on a boron-doped diamond electrode, with anodic current efficiencies of 20-40%. On the cathodic side, SPC was synthesized from carbonate through generation of H(2)O(2) by oxygen reduction on high-surface-area carbon felt. Cathodic current efficiency was 60% and nearly constant. The effect of Na(2)SiO(3) as a percarbonate stabilizer was studied during electrolysis and during storage, with 4 g/L giving the best performance.Electrochemical and Solid-State Letters 01/2009; 12(1). DOI:10.1149/1.3005555 · 2.15 Impact Factor
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ABSTRACT: A commercial NASICON pellet was tested for Na+-selective electrode in batch as well as in flow conditions, using two different hydrodynamic regimes: steady state and flow injection. The optimal hydrodynamic conditions to operate a homemade flow-trough cell (of wall-jet type) were established by performing amperometric measurements at a graphite electrode with the ferro/ferricyanide redox couple. Among the investigated supporting electrolytes (BaCl2, CaCl2, TEBA, TEAC, TRIS and HEPES), used for batch electrode calibration to Na+, TEAC showed the smallest interference versus Na+ together with a low limit of detection (9.2±0.5×10−5M). A comparison between the main analytical parameters (sensitivity, limit of detection and selectivity versus Li+, K+ and H+) observed for batch, steady state flow (SSF) and flow injection (FI) measurements showed that: (i) no significant differences were observed between batch and SSF conditions; (ii) in FI mode the sensitivity was higher, the limit of detection was slightly increased and, in the presence of BaCl2, the selectivity for the proton interference was improved.Sensors and Actuators B Chemical 06/2003; 91(1):67-75. DOI:10.1016/S0925-4005(03)00068-6 · 3.84 Impact Factor