Tuesday, 11 October 2022: 17:20
Room 302 (The Hilton Atlanta)
Electrocatalysis of redox reactions important to energy conversion and storage devices are widely reported in the literature [1–3]. In this work, the current-voltage curves (i-V curves) of V5+/V4+ redox reaction are recorded in a three-electrode configuration on Vulcan XC-72 modified glassy carbon rotating disk electrode at various temperatures. The enthalpy of activation (ΔH#) and pre-exponential factor at various overpotentials are estimated from the slope and intercepts of Eyring plots, respectively. Measured current is corrected for solution resistance and mass-transfer resistance to obtain the kinetic current. The analyses show that the electrocatalysis of V5+/V4+ redox reactions is due to the increase in the value of pre-exponential factor. The trend in the charge-transfer coefficients with the overpotential confirms the adsorbate effect on the electrode surface. Therefore, ΔH# and pre-exponential factor can be estimated from the Eyring plot only when there is no electrode surface coverage.
References:
- R. K. Singh, R. Devivaraprasad, T. Kar, A. Chakraborty and M. Neergat, J. Electrochem. Soc., 162, F489 (2015).
- B. Bapi, T. Kar, A. Chakraborty and M. Neergat, J. Electroanal. Chem., 805, 184 (2017).
- P. Leuaa, D. Priyadarshani, A.K. Tripathi and M. Neergat, J. Electroanal. Chem., 878, 114590 (2020).