1. National Institute of Materials and Chemical Research, Higashi 1-1, Tsukuba, Ibaraki 305-8565, Japan, Department of Thermal Energy and Hydropower, Norwegian University of Technology and Science, N-7034 Trondheim, Norway, and Department of Industrial Chemistry, Faculty of Science and Technology, Science University of Tokyo, 2641 Yamazaki, Chiba 278-8510, Japan