1. Center for Advanced Research of Energy Technology, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo 060-8628, Japan, Department of Research and Development, Hokkaido Electric Power Co., Inc., Tsuishikari 2-1, Ebetsu 067-0033, Japan, and Department of Molecular Engineering, Kyoto University, Yoshida-honcho, Sakyo-ku, Kyoto 606-8501, Japan