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Lookup NU author(s): Professor Ulrich Stimming
This is the authors' accepted manuscript of an article that has been published in its final definitive form by American Chemical Society, 2019.
For re-use rights please refer to the publisher's terms and conditions.
© 2019 American Chemical Society. The competition between the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) on a polycrystalline Pt (pc-Pt) electrode in weakly acidic solutions (pH ≈ 3) under the condition when both reactions are thermodynamically allowed is investigated using the rotating ring disk electrode (RRDE) technique and differential electrochemical mass spectrometry (DEMS). The partial currents of HER and ORR producing H2O2 or H2O are quantified. The results show that (i) ORR occurs preferentially in a diffusion-limited manner (either limited by the mass transfer of O2 or H+) and only the excess H+ not being consumed by the ORR can be converted to Had and H2 and (ii) at potentials negative of the onset of Had formation, the H2O2 production rate first increases and then decreases with the increasing overpotential. Possible origins for the H2O2 yield in the HER region are suggested. Present results demonstrate that combining DEMS and RRDE techniques can be powerful for deriving the intrinsic kinetics of individual processes in a complex electrochemical system.
Author(s): Chen W, Liao LW, Cai J, Chen Y-X, Stimming U
Publication type: Article
Publication status: Published
Journal: Journal of Physical Chemistry C
Print publication date: 12/12/2019
Online publication date: 24/11/2019
Acceptance date: 21/11/2019
Date deposited: 09/01/2020
ISSN (print): 1932-7447
ISSN (electronic): 1932-7455
Publisher: American Chemical Society
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