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Nanoparticle Surface Coverage Controls the Speciation of Electrochemically Generated Chlorine
Author(s) -
Kraikaew Pitchnaree,
Tanner Eden E. L.,
Sokolov Stanislav V.,
BatchelorMcAuley Christopher,
Holter Jennifer,
Young Neil P.,
Compton Richard G.
Publication year - 2016
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201600449
Subject(s) - chloride , chlorine , platinum , electrochemistry , chemistry , glassy carbon , inorganic chemistry , cyclic voltammetry , platinum nanoparticles , oxide , nanoparticle , electrode , materials science , catalysis , nanotechnology , organic chemistry
Cyclic voltammetry is used to investigate the oxidation of chloride on platinum nanoparticles. The electrochemical response of the nanoparticles drop‐cast onto a glassy carbon electrode is compared to that recorded at a platinum macroelectrode. The use of “nano”‐ and “macro”‐scale Pt reveals different ratios of the electrochemically formed products, chlorine (Cl 2 ) and the trichloride (Cl 3 − ) anion. This difference in the speciation is attributed to the chloride oxidation being a surface‐reaction‐limited process. For the situation in which there are a limited number of active sites available on the electrode, owing to low nanoparticle surface coverages, the sub‐diffusion‐limited currents result in higher chloride concentrations adjacent to the electrochemical interface. This excess chloride at the interface leads to the formation of the trichloride anion. The effect of surface oxide formation towards the chloride oxidation is also examined on both electrodes. Formation of platinum oxide serves to inhibit the rate of chloride oxidation.