Electrochemical Studies on the Lanthanides

란탄족 원소의 전기화학적 환원에 관한 연구 (제 1 보)

  • 박종민 (한남대학교 이과대학 화학과) ;
  • 강삼우 (한남대학교 이공대학 화학과) ;
  • 도이미 (한남대학교 화학과) ;
  • 한양수 (한남대학교 화학과) ;
  • 손병찬 (배재대학교 이공학부 화학과)
  • Published : 19901100


Voltammetric behavior of some light lanthanide ions (La$^{3+}$, Pr$^{3+}$, Nd$^{3+}$, Sm$^{3+}$, and Eu$^{3+}$) in various supporting electrolytes has been investigated by several electrochemical techniques. The peak potentials and the peak currents, their dependency on the concentration, temperature and pH effects, the reversibility of the electrode reactions are described. The reduction of La$^{3+}$, Pr$^{3+}$ and Nd$^{3+}$ in 0.1 M lithium chloride proceeds by a three-electron change directly to the metallic state (Ln$^{3+}$ + 3e- → Ln$^0$) and charge transfer is totally irreversible. However, the reduction of Sm$^{3+}$ in 0.1 M tetramethylammonium iodide and Eu$^{3+}$ in 0.1 M lithium chloride proceeds in two stages (Ln$^{3+}$ + e- → Ln$^{2+}$ and Ln$^{2+}$ + 2e- → Ln$^0$). At pH values lower than ca.4 the hydrated lanthanide species (Ln(OH)$^{2+}$) reduced before the lanthanide ions (Ln$^{3+}$) due to the catalytic effect of hydrogen ions, and peak current increase with in the order Eu$^{3+}$ < Sm$^{3+}$ < Nd$^{3+}$ < Pr$^{3+}$ < La$^{3+}$ in differential pulse polarography. Some representative plots of $i_{pc}V^{-1/2} (proportional to current function) vs. V show considerable influence of hydrogen ion/lanthanide ion concentration in cyclic voltammetry. It is shown that a reaction of lanthanide ions with proton and/or water and catalytic reaction is enhanced at lower pH and at decreased lanthanide ion concentration.



  1. Zh. Neorg. Khim. v.2 S. I. Yakubson;N. A. Kastromina
  2. J. Am. Chem. Soc. v.71 A. W. Swensen;G. Blocker
  3. 日本化學會誌 v.80 岩瀨秋雄
  4. 日本化學會誌 v.81 岩瀨秋雄
  5. 日本化學會誌 v.81 岩瀨秋雄
  6. J. Electroanal. Chem. v.89 E. Steeman;E. Temmerman;F. Verbeek
  7. J. Electroanal. Chem. v.89 E. Steeman;E. Temmerman;F. Verbeek
  8. J. Am. Chem. Soc. v.79 I. M. Kolthoff;J. F. Coetzee
  9. J. Electroanal. Chem. v.100 B. Behr;Z. Borkowska;H. Elzanowska
  10. Handbook of Analytical Chemistry L. Meites
  11. Collect Czech. Chem. Commun. v.6 D. Ilkovic
  12. Chem. Abstr. v.51 S. I. Yakubson;N. A. Kastromina
  13. Polarography and Other Voltammetric Methods T. Riley;A. Waton
  14. 日本化學會誌 v.78 岩瀨秋雄
  15. The Hydrolysis of Cations C. F. Baes, Jr.;R. F. Mesmer
  16. J. Electroanal. Chem. v.14 B. Timmer;M. Sluyters-Rehbach;J. H. Sluyters
  17. Anal. Chem. v.36 R. S. Nicholson;I. Shain
  18. Anal. Chem. v.44 F. H. Reyerlein;R. S. Nicholson
  19. Mordern Polarographic Methods in Analytical Chemistry A. M. Bond
  20. Anal. Chem. v.36 R.F. Large;A. Timnick
  21. Angew. Chem. v.50 W. Noddack;A. Bruckl
  22. Polarography I. M. Kolthoff;J. J. Lingane
  23. J. Am. Chem. Soc. v.70 A. Timnick;G. Glocker
  24. J. Am. Chem. Soc. v.70 C. R. Estee;G. Glocker
  25. Anal. Chim. Acta v.12 A. Purushottam;S. V. Raghave Rav
  26. Collect Czech. Chem. Commun. v.24 L. Treindl