Abstract
In this work, the role of carbon in alkaline oxygen electrocatalysis was investigated using an oxygen-deficient, perovskite-structured oxide catalyst, La0.6Sr0.4CoO3−δ (LSCO), mixed in different mass ratios with Vulcan carbon (XC-72R, referred to as XC-72) to observe the effect of the LSCO-to-XC-72 ratio (LSCO/XC-72) on the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics. Six different LSCO/XC-72 mass ratios were designed for the study as follows: 1:0 (pure LSCO), 10:1, 7:1, 5:1, 2:1 and 1:1. A thin-film oxygen electrode consisting of the LSCO/XC-72 catalysts was characterized in 0.1 M KOH solution using cyclic voltammetry (CV), rotating disk electrode (RDE) based linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). A physics-based, generalized electrochemical model was used to establish the charge-transfer mechanism and to obtain the electrode kinetic transfer coefficients and exchange current densities for the electrochemical reactions considered. The results show that the oxygen electrocatalysis process depends quite heavily on the carbon content in the catalyst, and there appears to be a synergistic effect between the perovskite-oxide and the XC-72, with a transition from the two-step, 2e− pathway to the direct 4e− transfer pathway as carbon content increases.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
