A Highly Efficient Bifunctional Catalyst for Alkaline Air-Electrodes Based on a Ag and Co3O4 Hybrid: RRDE and Online DEMS Insights
[Display omitted] Enhanced catalytic activity towards oxygen reduction (ORR) and evolution (OER) reactions has been achieved by combination of spinel Co3O4 nanoparticles with Ag particles. Quasi-stationary polarization curves showed that the mixed catalyst, Ag+Co3O4 (10wt%), outperformed its compone...
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Published in | Electrochimica acta Vol. 151; pp. 332 - 339 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier Ltd
01.01.2015
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Subjects | |
Online Access | Get full text |
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Summary: | [Display omitted]
Enhanced catalytic activity towards oxygen reduction (ORR) and evolution (OER) reactions has been achieved by combination of spinel Co3O4 nanoparticles with Ag particles. Quasi-stationary polarization curves showed that the mixed catalyst, Ag+Co3O4 (10wt%), outperformed its components. Rotating ring-disc electrode (RRDE) measurements revealed a negligible peroxide species formation and a 4-electron pathway for ORR. A tafel slope of ca. 75mVdec−1 has been observed. The overpotential for ORR at 10% Co3O4 catalyst is ca. 70mV lower than that of Ag and only ca. 80mV higher than that of the commercial Pt catalyst. DEMS technique provided a direct evidence for oxygen evolution at these bimetallic catalysts. This hybrid is therefore one of the (or even the) most active, carbon-free, durable, non-precious ORR and OER electrocatalysts reported to date. |
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ISSN: | 0013-4686 1873-3859 |
DOI: | 10.1016/j.electacta.2014.11.017 |