Nitrogen adsorption of cobalt-incorporated MCM-41 materials after compression at high pressure

Abstract

Cobalt-incorporated MCM-41 samples were synthesized using different concentrations of Cobalt (Si/Co ratios from 20 to 100) and a direct hydrothermal method. To investigate the mechanical stability of Co-MCM-41 samples, nitrogen adsorption-desorption isotherms were measured after compressing the sample under high pressure. X-Ray diffraction patterns of Co-MCM-41 samples obtained after calcination, but before compressing, showed four diffraction peaks irrespective of the cobalt loading; this finding indicates that the mesoporous silica has a highly ordered hexagonal symmetry. After compressing the Co-MCM-41 sample (Si/Co=50) up to 392 MPa, the surface area deceased from 1343 to 782 m(2)/g. However, the mesopore structure of the Co-MCM-41 sample was maintained and the pore size (3.7 nm) was the same as that of the pristine sample. These findings suggest that Co-incorporated mesoporous silica materials are very sustainable to compression at high pressure.