1. Key Laboratory of Renewable Energy Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development Guangzhou Institute of Energy Conversion Chinese Academy of Sciences Guangzhou 510640 P. R. China
2. Guangzhou Institute of Energy Conversion University of Chinese Academy of Sciences Beijing 100049 P. R. China
3. Department of Thermal Science and Energy Engineering University of Science and Technology of China Hefei 230031 P. R. China
4. School of Materials Science and Energy Engineering Guangdong Key Laboratory for Hydrogen Energy Technologies Foshan University Foshan 528000 P. R. China