1. Division of Materials Science and Chemistry, Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo, Kumamoto 860-8555, Japan
2. Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo, Kyoto 615-8245, Japan
3. Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyotodaigaku Katsura, Nishikyo, Kyoto 615-8510, Japan
4. Advanced Ceramics Research Center, Nagoya Institute of Technology, Tajimi, Gifu 507-0071, Japan
5. Inorganic Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Moriyama, Nagoya 463-8560, Japan
6. Mitsui Mining & Smelting Co., Ltd., Ageo, Saitama 362-0025, Japan
7. Umicore Shokubai Japan Co., Ltd., Chuo, Kobe, Hyogo 650-0047, Japan
8. Suzuki Motor Corporation, Minami, Hamamatsu, Shizuoka 432-8611, Japan
9. Mitsubishi Motors Corporation, Okazaki, Aichi 444-8501, Japan