Dissolution of partially immersed nickel during in situ oxidation in molten carbonate: cyclic, stripping and square wave voltammetry measurements

Yazici M. S., Selman J.

JOURNAL OF ELECTROANALYTICAL CHEMISTRY, cilt.457, sa.1-2, ss.89-97, 1998 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 457 Sayı: 1-2
  • Basım Tarihi: 1998
  • Doi Numarası: 10.1016/s0022-0728(98)00126-0
  • Dergi Adı: JOURNAL OF ELECTROANALYTICAL CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED)
  • Sayfa Sayıları: ss.89-97
  • Anahtar Kelimeler: molten carbonate, dissolution, nickel, voltammetry, NIO SOLUBILITY, LI/K CARBONATE, BEHAVIOR, OXIDE, ELECTRODE
  • İstanbul Teknik Üniversitesi Adresli: Evet

Özet

Electrochemical techniques such as cyclic voltammetry, stripping voltammetry and square wave voltammetry were used to determine the product of concentration and diffusivity of Ni2+ ions in 62% Li2CO3 + 38% K2CO3 electrolyte mixture under standard gas composition(15% O-2 + 30% CO2) at 650 degrees C. In the case of cyclic voltammetry and stripping voltammetry, dissolved nickel is first deposited on a gold electrode at negative potentials, then dissolved by scanning through positive potentials. Square wave voltammetry is also used as a more precise method to compare the cD(1/2) product between electrochemical techniques. The magnitude of the peak current from current-potential data is related to scan rate, diffusivity and concentration of nickel ions in the melt. Values of cD(1/2) Obtained by these techniques are in good agreement. The saturation concentrations calculated from our measurements (0.5-1 mu mol cm(3)) depend on the diffusion coefficient used in the calculations, but agree with literature values in order of magnitude. (C) 1998 Elsevier Science S.A. All rights reserved.