Calculation of XRD patterns of simulated FDU-15, CMK-5, and CMK-3 carbon structures

XRD patterns of model structures of the ordered mesoporous carbon materials FDU-15, CMK-5, and CMK-3 have been calculated. The structure models had been derived by filling tubular (CMK-5), rod-like (CMK-3), or channel wall (FDU-15) spaces in a given unit cell with carbon atoms. The generated carbon sites then have been used for the calculation of the XRD patterns. It could be shown that XRD patterns of CMK-5 materials vary substantially with variation of the tube diameter and carbon wall thickness. For a certain range of tube diameters, the XRD patterns do not resemble those of CMK-3 or FDU-15. The carbon material FDU-15 is isostructural to the silica SBA-15, CMK-3 is the negative replica of SBA-15. XRD patterns of CMK-3 and FDU-15 models also vary with varying rod or pore diameter but the changes are not as significant as for different CMK-5 models. As expected, the XRD patterns of FDU-15 and CMK-3 resemble each other very much for a given lattice parameter if the rods of CMK-3 are of the same size as the pore diameters of FDU-15. (C) 2008 Elsevier Inc. All rights reserved.