1. Guangzhou Institute of Energy Conversion; Chinese Academy of Sciences; Guangzhou 510640 PR China
2. Guangdong Key Laboratory of New and Renewable Energy Research and Development; Guangzhou 510640 PR China
3. Department of Chemical Engineering; Nagoya University; Nagoya, Aichi 464-8603 Japan
4. College of Science and Engineering; Kanazawa University; Kanazawa, Ishikawa 920-1192 Japan