1. School of Materials Science and Engineering State Key Laboratory of Heavy Oil Processing China University of Petroleum (East China) Qingdao 266580 P.R. China
2. College of New Energy and Materials State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing 102249 P.R. China
3. Clean Nano Energy Center State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 P.R. China
4. CNOOC Tianjin Chemical Research and Design Institute Co., Ltd Tianjin 300131 P.R. China