An experimental and theoretical study of electroreduction of oxygen to hydrogen peroxide is presented. The experimental measurements of nitrided Ketjenblack indicated an onset potential for reduction of approximately 0.5 V (SHE) compared to the onset potential of 0.2 V observed for untreated carbon. Quantum calculations on cluster models of nitrided and un-nitrided graphite sheets show that carbon radical sites formed adjacent to substitutional N in graphite are active for O2 electroreduction to H2O 2 via and adsorbed OOH intermediate. The weak catalytic effect of untreated carbon is attributed to weaker bonding of OOH to the H atom-terminated graphite edges. Substitutional N atoms that are far from graphite sheet edges will be active, and those that are close to the edges will be less active. Interference from electrochemical reduction of H atoms on the reactive sites is considered, and it is shown that in the potential range of H2O 2 formation the reactive sites are not blocked by adsorbed H atoms. © 2006 American Chemical Society.
CITATION STYLE
Sidik, R. A., Anderson, A. B., Subramanian, N. P., Kumaraguru, S. P., & Popov, B. N. (2006). O2 reduction on graphite and nitrogen-doped graphite: Experiment and theory. Journal of Physical Chemistry B, 110(4), 1787–1793. https://doi.org/10.1021/jp055150g
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