1. Interdisciplinary Research Center of Biology & Catalysis School of Life Sciences Northwestern Polytechnical University Xi'an 710072 P. R. China
2. College of Chemical Engineering Xiangtan University Xiangtan 411105 P. R. China
3. State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences Taiyuan 030001 P. R. China
4. Analytical & Testing Center Northwestern Polytechnical University Xi'an 710072 P. R. China
5. Key Laboratory of Renewable Energy Guangdong Key Laboratory of New and Renewable Energy Research and Development Guangzhou Institute of Energy Conversion Chinese Academy of Sciences Guangzhou 510640 P. R. China