Because of the emerging global warming and environmental pollutions, hydrogen as a renewable and sustainable energy source has expected to solve those global issues [1]. In particular, hydrogen-fueled fuel cells are one of the most promising electrochemical energy conversion devices due to their high efficiency and negligible pollution emissions. Furthermore, URFCs that produce both hydrogen fuel and electricity in one single device have received great attentions these days. However, URFCs have several technical barriers for making commercialization, such as sluggish catalytic kinetics of oxygen reduction (ORR) and oxygen evolution reactions (OER) [2]. Up to now, noble metal (e.g Pt/C and IrO₂)-based electrocatalysts have still used to get high performances of OER and ORR, even though these metals have critical drawbacks such as expensive price and low durability [3]. In order to overcome these problems, many transition metal oxide-based materials have studied as bifunctional electrocatalysts [4, 5]. In this work, in order to improve electrocatalytic activity of transition metal oxide-based catalysts, high surface area carbon-based supporting materials such as graphene or carbon nanofiber are considered [6]. The graphene-carbon nanofiber-suppported transition oxide catalysts are synthesized by the hydrothermal method and analyzed by various physicochemical and electrochemcial tools [7].

References

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2. K. Fominykh, P. Chernev, I. Zaharieva, J. Sicklinger, G. Stefanic, M. Döblinger, A. Müller, A. Pokharel, S. Böcklein, C. Scheu, T. Bein, and D. Fattakhova-Rohlfing, ACS. Nano., 5, 5180 (2015).
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