Examples



mdbootstrap.com



 
Статья
2018

Double Current Maxima Formed under Linear Potential Sweep Conditions in Acetic Acid Solutions at pH < 2.5


A. Survila A. Survila , S. Kanapeckaite S. Kanapeckaite , K. Mažeika K. Mažeika
Российский электрохимический журнал
https://doi.org/10.1134/S1023193518010081
Abstract / Full Text

The kinetics of hydrogen evolution on a copper electrode in acetic acid solutions is studied by the method of linear potential sweep. At рН < 2.5, double current peaks are observed with the height directly proportional to both √v (v is the potential sweep rate) and the total concentration of proton donors and acceptors. Upon the transition from the copper electrode to the platinum electrode, the overpotential of this process considerably decreases, but the shape of current peaks remains unchanged. The analysis of kinetics of acetic acid dissociation points to the high degree of lability of this system, which allows the relationship between the surface concentrations of its components to be expressed through the corresponding equilibrium constants. At certain potentials, significant changes in the surface pH are observed, which favor the appearance of an additional current peak in the cathodic chronovoltammogram. The Tafel plots normalized with respect to the surface concentration of hydrogen ions allow the following values of kinetic parameters to be obtained: i0 ~ 0.3 nA/cm2 and αc = 0.75. Chronovoltamograms simulated with the use of these values demonstrate double maximums which adequately agree with experimental data.

Author information
  • Center for Physical Sciences and Technology, Institute of Chemistry, Saulėtekio ave. 3, Vilnius, LT, 10222, Lithuania

    A. Survila, S. Kanapeckaite & K. Mažeika

References
  1. Nikolic, N.D., Fundamental aspects of copper electrodeposition in the hydrogen co-deposition range, Zast. Mater., 2010, vol. 51, no. 4, p.197.
  2. Survila, A., Electrochemistry of Metal Complexes. Applications from Electroplating to Oxide Layer Formation, Weinheim: Wiley-VCH, 2015.
  3. Kanzaki, Y., Tokuda, K., and Bruckenstein, S., Dissociation rates of weak acids using sinusoidal hydrodynamic modulated rotating disk electrode employing Koutecky–Levich equation, J. Electrochem. Soc., 2014, vol. 161, no. 12, p. H770.
  4. Daniele, S., Baldo, M.A., and Simonetto, F., Assessment of linearity between steady-state limiting current and analytical concentration of weak acids in the reaction of hydrogen evolution, Anal. Chim. Acta, 1996, vol. 331, no. 1, p.117.
  5. Daniele, S., Lavagnini, I., Baldo, M.A., and Magno, F., Steady state voltammetry at microelectrodes for the hydrogen evolution from strong and weak acids under pseudo-first and second order kinetic conditions, J. Electroanal. Chem., 1996, vol. 404, p.105.
  6. Daniele, S., Lavagnini, I., Baldo, M.A., and Magno, F., Voltammetry for reduction of hydrogen ions from mixtures of mono-and polyprotic acids at platinum microelectrodes, Anal. Chem., 1998, vol. 70, no. 2, p.285.
  7. Survila, A. and Kanapeckaite, S., LPS current peaks arising from hydrogen evolution involving proton donors, Chemija, 2016, vol. 27, p.158.
  8. Survila, A. and Kanapeckaite, S., Kinetics of hydrogen evolution on copper electrode in acetic and gluconic acid solutions, Chemija, 2016, vol. 27, p.164.
  9. Survila, A. and Kanapeckaite, S., Effect of camphor on Cu(II) reduction kinetics in acid solutions, Electrochim. Acta, 2015, vol. 168, p.1.
  10. Filella, M., van Leeuwen, H.P., Buffle, J., and Holub, K., Voltammetry of chemically heterogeneous metal complex systems. Part II. Simulation of the kinetic effects induced on polarographic waves, J. Electroanal. Chem., 2000, vol. 485, p.144.
  11. Santos, E., Lundin, A., Pötting, K., Quaino, P., and Schmickler, W., Model for the electrocatalysis of hydrogen evolution, Phys. Rev. B, 2009, vol. 79, p. 235436.
  12. Santos, E., Pötting, K., Lundin, A., Quaino, P., and Schmickler, W., Hydrogen evolution on single-crystal copper and silver: a theoretical study, ChemPhysChem, 2010, vol. 11, no. 7, p. 1491.
  13. Macdonald, D.D., Transient Techniques in Electrochemistry, New York: Plenum, 1977.
  14. Davison, W., Defining the electroanalytically measured species in a natural water sample, J. Electroanal. Chem., 1978, vol. 87, p.395.
  15. Carofiglio, T., Magno, F., and Lavagnini, I., Microelectrode voltammetry for studying host-guest complexation equilibria. An analysis of the possibilities of the method, J. Electroanal. Chem., 1994, vol. 373, p.11.
  16. Danielle, S., Bragato, C., and Baldo, M.A., Steadystate voltammetry for the reduction of labile metal complexes in the absence and presence of different concentrations of supporting electrolyte, J. Electroanal. Chem., 1997, vol. 439, p.153.
  17. Van Leeuwen, H.P. and Pinheiro, J-P., Lability criteria for metal complexes in microelectrode voltammetry, J. Electroanal. Chem., 1999, vol. 471, p.55.
  18. Van Leeuwen, H.P., Revisited: the conception of lability of metal complexes, Electroanalysis, 2001, vol. 13, no. 10, p.826.
  19. Nicholson, R.S. and Shain, I., Theory of stationary electrode polarography. Single scan and cyclic methods applied to reversible, irreversible, and kinetic systems, Anal. Chem., 1964, vol. 36, no. 4, p.706.
  20. Fleischmann, M., Lasserre, F., Robinson, J., and Swan, D., The application of microelectrodes to the study of homogeneous processes coupled to electrode reactions: Part I. EC and CE reactions, J. Electroanal. Chem., 1984, vol. 177, p.97.
  21. Frese, U. and Stimming, U., Hydrogen evolution on copper, silver and gold electrodes in aqueous perchloric acid from 130 to 300 K, J. Electroanal. Chem., 1986, vol. 198, p.409.
  22. Sharifi-Asi, S. and Macdonald, D.D., Investigation of the kinetics and mechanism of the hydrogen evolution reaction on copper, J. Electrochem. Soc., 2013, vol. 160, p. H382.
  23. Survila, A. and Stasiukaitis, P.V., Linear potential sweep voltammetry of electroreduction of labile metal complexes. I. Back-ground model, Electrochim. Acta, 1997, vol. 42, no. 7, p. 1113.