[1] Univ Electrocommun, Innovat Res Ctr Fuel Cells, Chofu, Tokyo 1828585, Japan
[2] Univ Electrocommun, Dept Engn Sci, Chofu, Tokyo 1828585, Japan
[3] Honda Res & Dev Co Ltd, Haga, Tochigi 3213393, Japan
[4] SPring 8, Japan Synchrotron Radiat Res Inst, Koto Ku, Sayo, Hyogo 6795198, Japan
[5] Inst Mol Sci, Okazaki, Aichi 4448585, Japan