In the present study, metal foam is used as the anode of a direct coal fuel cell (DCFC) system. A discrete element method-computational fluid dynamics (DEM-CFD) approach is used to assess the effects of the porous metal and particle diameter on the development of a triple phase boundary (TPB) between the coal, electrolyte, and anode. DEM-CFD analyses are conducted with various diameters of particles ranging from 10 to 350 mu m. It is found that the number of contacts between the particles and metal ligaments decreases with increases in the particle size; however, the contact number increases after it passes a minimum number. The minimum number of contacts appears to increase as the pore size increases. Based on these results, an operable region map is developed that demonstrates the relationship between the particle size and pore size of porous metals. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.