1. Key Laboratory of Coal Science and Technology
2. Ministry of Education and Shanxi Province
3. Taiyuan University of Technology
4. Taiyuan 030024
5. China
6. School of Materials Science and Engineering
7. Shandong University
8. Jinan 250100
9. State Key Laboratory of Coal Conversion
10. Institute of Coal Chemistry, Chinese Academy of Sciences
11. Taiyuan 030001
12. University of Chinese Academy of Sciences