1. State Key Laboratory of Coal Conversion, Institute of Coal ChemistryChinese Academy of Sciences Taiyuan 030001 People's Republic of China
2. College of Chemistry and Chemical EngineeringTaiyuan University of Technology Taiyuan 030024 People's Republic of China
3. Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi ProvinceTaiyuan University of Technology Taiyuan 030024 People's Republic of China