1. State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology (HUST), Wuhan 430074, China, Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 16-1, Onogawa, Tsukuba 305-8569, Japan and Department of Applied Chemistry, Chubu University, 1200 Matsumoto-cho, Kasugai 487-8501, Japan