MCM-41 and the BdB corrected Kelvin equation for accurate mesopore size distributions from gas adsorption data

In this paper the adaptation of the classical Kelvin equation is discussed and applied to synthesised MCM-41 materials. Other analytical techniques as X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) are used to confirm the results. The correction made by Broekhoff-De Beer (BdB) is a correction for forces emanating from the walls of the adsorbent and results in increasing pore size. The results obtained by the nitrogen adsorption experiments using the BdB equation look promising. A good correlation is found between the results of the BdB equation and the other analytical techniques. Corrections up to almost 40% are found for mesopores in the pore size range up to 4 nm. A good similarity is also found between the corrected Kelvin equation and DFT incorporating cylindrical pore geometry.