Monday, 10 October 2022: 11:00
Room 302 (The Hilton Atlanta)
Oxygen reduction reaction (ORR) is an utmost important reaction in fuel cells technology [1]. The slow kinetics of ORR retards the overall process and thus various Pt-based catalysts are used to catalyse the reaction. However, the cost associated with precious metals makes it difficult to use it on large-scale basis [2]. Thus, research is mainly focused on the development of non-precious metal-free catalysts (NPMCs) [3, 4]. In this work, ORR is investigated on Vulcan-XC 72 carbon and metal-free nitrogen-doped carbon electrodes in 0.1 M KOH in the temperature range of 293–333 K. The kinetic parameters enthalpy of activation (ΔH#) and pre-exponential factor (Af) is obtained from the Arrhenius analyses. The enhancement of catalytic activity with nitrogen doping is explained on the basis of the kinetic parameters. It is observed that both ΔH# and Af are stronger functions of overpotential in case of N/C than that with pristine carbon, and explains the faster reaction rate of doped-carbon towards ORR. Such analysis is important in terms of kinetics, especially for NPMCs, where true measure of electrochemical surface area is not established yet.
References
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- Bera, T. Kar, A. Chakraborty, and M. Neergat, J. Electroanal. Chem., 805, 184–192 (2017).
- Chakraborty, R. Devivaraprasad, B. Bera, M. Neergat, Phys.Chem.Chem.Phys., 19, 25414−25422 (2017).