1. Department of Chemistry and Chemical Engineering, Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry & Technology, Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry, Ministry of Education, The Youth Innovation Team of Shaanxi Universities, Shaanxi University of Science and Technology, Xi'an, Shaanxi 710021, P. R. China
2. State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, P. R. China
3. University of Chinese Academy of Sciences, Beijing 100049, P. R. China