Preparation of TaOx by Electrochemical Technique and Its Application to Electrocatalytic Oxygen Reduction

Wednesday, 8 October 2014: 15:00
Expo Center, 1st Floor, Universal 14 (Moon Palace Resort)
Z. Awaludin, M. Safuan, X. Ye, T. Okajima, and T. Ohsaka (Tokyo Institute of Technology)
Here we demonstrate a new and simple technique for preparing a tantalum oxide (TaOx)-based electrocatalyst at room temperature for oxygen reduction reaction (ORR) by electrochemical technique [1-4]. The Ta2O5 on the as-prepared deposits was reduced by electrolysis at potential of −0.6 V vs. Ag|AgCl|KCl(sat.) for 12 h generating a smoother and thinner layer of its reduced species (TaOx) (Fig. 1). The treated TaOx exhibits a high ORR activity in acidic and alkaline solutions as seen from a fairly high onset potential (0.87 V vs. RHE) in comparison with that (0.98 V) at a commercially available Pt/C catalyst. By rotating ring-disk electrode voltammetric measurements, it can be concluded that this oxide possesses an almost four-electron ORR electrocatalysis at potential above 0.8 V vs. RHE and a two-electron ORR becomes significant gradually as the potential is increased negatively. The obtained results demonstrate that the present “treated” TaOx is expected as a promising electrocatalyst for ORR in PEMFCs even though its electrocatalytic performance needs to be improved significantly further to replace the Pt/C.   




Fig. 1 Schematic illustration of the electrochemical preparation of TaOxelectrocatalyst for ORR.




The present research was financially supported by Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.


1) Z. Awaludin, M. Suzuki, J. Masud, T. Okajima and

T. Ohsaka, J. Phys. Chem. C, 115, 25557 (2011).

2) Z. Awaludin, J.-M. Sheng Moo, T. Okajima and

T. Ohsaka, J. Mater. Chem. A, 1, 14754 (2013).

3) J. G. S. Moo, Z. Awaludin, T. Okajima and T. Ohsaka, J. Solid State Electrochem., 17, 3115 (2013).

4) Z. Awaludin, T. Okajima and T. Ohsaka,

J. Power Sources, in press.