In order to reflect the structural features of the porous matrix, such values of PFG parameter can be obtained by performing diffusion measurements using weak-interacting molecules, such as hydrocarbons, which have previously been reported for MN 200 and MN 500 using PFG-NMR [22]: averagely 3.4 ± 0.1 and 2.4 ± 0.1 for macropores and 14.7 ± 1.7 and 12.8 ± 1.3 for micropores of MN 200 and MN 500, respectively.