High oxygen reduction activity of few-walled carbon nanotubes with low nitrogen content

1. Borghei, M.
2. Kanninen, P.
3. Lundahl, M.
4. Susi, T.
5. Sainio, J.
6. Anoshkin, I.
7. Nasibulin, A.
8. Kallio, T.
9. Tammeveski, K.
10. Kauppinen, E.
11. Ruiz, V.