1. College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, P. R. China
2. Key Laboratory of Chemistry and Chemical Engineering on Heavy Carbon Resources of Yili Kazakh Autonomous Prefecture, Yili Normal University, Yining, Xinjiang 835000, P. R. China
3. State Key Laboratory of Coal Mining and Clean Utilization, Beijing 100013, P. R. China