Uniformly electrodeposited a-MnO2 film on super-aligned electrospun carbon nanofibers as a bifunctional catalyst for the oxygen reduction reaction

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Jianjun Wei, Associate Professor (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/

Abstract: Metal oxide/carbonaceous nanomaterials are promising candidates for the oxygen reduction in energy converting systems. However, inhomogeneous surface coverage allows hydrogen peroxide to escape into the bulk solution due to unstable metal or metal oxide/carbonaceous nanomaterial synthesis, which limits their performance in fuel cells. Here, we show that the above problems can be mitigated through a stable low-current electrodeposition of MnO2 on super-aligned electrospun carbon nanofibers (ECNFs). The key to our approach is coupling a self-designed four steel poles collector for aligned ECNFs and a constant low-current (45 µA) electrodeposition technique for 4 h to form a uniform Na+ induced a-MnO2 film. By using the cyclic voltammetry to proceed the electrocatalytic oxygen reduction reaction (ORR), the bifunctional catalysts show a 3.84-electron pathway due to the rapid decomposition of hydrogen peroxide by the uniform a-MnO2 film and ending with formation of water. This research may enable a practical catalyst with a large number of cycling of oxygen reduction/regeneration to reduce the risk of the fuel cell degradation and an effective confinement of oxygen and hydrogen peroxide in the catalyst matrix to maximize the energy output of the fuel cell. [The original abstract for this article contains (characters/images) that cannot be displayed here. Please click on the link below to read the full abstract and article.]

Additional Information

Publication
Electrochimica Acta, 2017, 256, 232-240
Language: English
Date: 2017
Keywords
MnO2, Electrospun carbon nanofibers, Bifunctional catalyst, Oxygen reduction reaction, Fuel cells

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