1. College of Chemical and Environmental EngineeringShandong University of Science and Technology, Qingdao Shandong 266590 China
2. Department of ChemistryPurdue University, Brown Building 560 Oval Drive, West Lafayette Indiana 47907 United States
3. State Key Laboratory of High-efficiency Coal Utilization and Green Chemical EngineeringNingxia University, Yinchuan Ningxia 750021 China
4. Key Laboratory of Coal Processing and Efficient UtilizationMinistry of EducationChina University of Mining & Technology, Xuzhou Jiangsu 221116 China
5. Polymer Petroleum and Coal Chemistry GroupMaterials Science and Technology DivisionCSIR-North East Institute of Science & Technology Jorhat 785006 India