1. Toyota Fuel Cell Hybrid Vehicle www.toyota.co.jp/en/tech/environment/fchv/fchv12.html (2004).
2. United States Council for Automotive Research Hydrogen as a Fuel; www.uscar.org/Media/2002issue2/hydrogen.htm (2004).
3. European Fuel Cell Forum 2003
4. Materials and methods are available as supporting material on Science Online.
5. N. Minh, in Proc. 8th Int. Symp. on Solid Oxide Fuel Cells, S. C. Singhal, M. Dokiya, Eds. (Electrochemical Society, Pennington, NJ, 2003), p. 43.