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.com
Volume 7
Biosensors Journal
ISSN: 2090-4967
Electrochemistry 2018
June 11-12, 2018
June 11-12, 2018 | Rome, Italy
4
th
International Conference on
Electrochemistry
Novel manganese dioxide-based electrocatalyst formulations for bifunctional oxygen reduction and
evolution reaction activity
Elod L Gyenge
1, 2
1
University of British Columbia, Canada
2
Catalyst Square Materials Ltd., Canada
D
evelopment of highly active, durable and cost-efficient bifunctional electrocatalysts for the oxygen reduction and evolution
reactions (ORR and OER) is of outmost importance for commercialization of rechargeable metal-air batteries (e.g., Zn-
air, Al-air, Mg-air, Li-air) and regenerative H
2
-O
2
fuel cells. Manganese dioxide (MnO
2
), a low cost and abundant material, has
been intensely studied as ORR electrocatalyst in alkaline media. Regarding the bifunctional ORR and OER electrocatalytic
performance, however, enhancement of the activity (e.g., lower surface overpotential at practical current densities above 100
mA cm
-2
) and improvement of the long-term stability are required for potential implementation in commercial systems. The
purpose of this study is to present novel approaches for tuning the MnO
2
performance with co-catalyst addition, potassium
ion doping and support effect (e.g., graphene and graphitized carbon). The combination of MnO
2
with structurally different
oxide co-catalysts such as perovskite (LaCoO
3
) or fluorite-type oxide (Nd
3
IrO
7
) produces a synergistic catalytic effect
improving the bifunctional (ORR and OER) activity compared to the individual oxides. Doping of the oxide catalyst with
potassium ions, either by long-term exposure to 6 M KOH or potential driven insertion (PDI), increases further the activity
and durability as revealed in accelerated degradation experiments. Optimizing the MnO
2
electrodeposition conditions can
produce nanostructured morphologies that are favorable for ORR and OER activity. The electrochemical studies are supported
by extensive surface analysis (SEM, TEM, XPS, EDX, EELS). This work reveals new oxygen electrode catalyst formulations for
rechargeable metal-air batteries and regenerative fuel cells.
Figure 1:
Tafel plots for the oxygen evolution reaction (OER) using diverse oxide electrocatalysts (6 M KOH) (293 K). The numbers indicate the calculated apparent Tafel slopes.
Recent Publications:
1. Hosseini Benhangi P, Alfantazi A and Gyenge E (2014) Electrochimica Acta 123:42-50.
2. Hosseini Benhangi P, Garcia Contreras M A, Alfantazi A and Gyenge E (2014) Journal of the Electrochemical Society
162: F1356-1366.
3. Hosseini Benhangi P, Kung C, Alfantazi A and Gyenge E (2017) ACS Applied Materials and Interfaces 9:26771-26785.
Biography
Elod L Gyenge is a Professor in the Department of Chemical and Biological Engineering and Clean Energy Research Centre at the University of British Columbia,
Vancouver, Canada. His research is focused on electrocatalysis and electrochemical engineering for improving the performance of electrochemical power sources
and electrosynthetic processes. His research led to many innovations for a variety of electrochemical systems including diverse fuel cells and rechargeable
batteries, and electrosynthesis of hydrogen peroxide. The research materialized in over 75 refereed research publications in peer reviewed journals, over 40 invited
presentations and 10 patents and patent applications. He has received a number of awards and recognitions, among them the Japanese Society for Promotion
of Science (JSPS) Fellowship at Osaka University and Elisabeth and Leslie Gould Endowed Professorship at UBC (2007-2014). Since 2016 he is also cross-
appointed Professor in the Graduate School of Engineering at Osaka University, Japan. He is a Co-Founder of two companies: Catalyst Square Materials Ltd. and
Agora Energy Technologies Ltd
elod.gyenge@ubc.caElod L Gyenge, Biosens J 2018, Volume 7
DOI: 10.4172/2090-4967-C1-002