As a promising high-temperature fuel cell, the direct carbon fuel cell (DCFC) has a much higher efficiency and lower emissions compared with conventional coal-fired power plants. In the present DCFC system, four Australian coals from Central Queensland are successfully tested at 600-800 degrees C. The electrochemical performances of these coals are highly dependent on their intrinsic properties, such as chemical composition, surface area, concentrations of oxygen-containing surface functional groups and the nature of mineral matter in their ashes. Impurities such as Al2O3 and SiO2 lead to an inhibitive effect during the anodic reaction in the DCFC, while CaO, MgO and Fe2O3 exhibit a catalytic effect on the electrochemical oxidation of carbon. (C) 2010 Elsevier BM. All rights reserved.