1. Key Laboratory of Coal Processing and Efficient Utilization, Ministry of Education, China University of Mining & Technology, Xuzhou 221116, Jiangsu, People’s Republic of China
2. Department
of Chemistry, Zaozhuang University, Zaozhuang 277160, Shandong, People’s Republic of China
3. State
Key Laboratory of Heavy Oil Processing, China University of Petroleum, Qingdao 266555, Shandong, People’s Republic of China