<p>This study aimed to prepare microporous silica and modified silica materials, including methylated and cobalt-doped varieties. The preparation process involved the sol–gel method, utilizing acid-catalyzed hydrolysis and condensation of tetraethylorthosilicate and methyltriethoxysilane, along with cobalt doping within the methylated silica matrix. The impact of hydrotreatment on the structure of the cobalt-doped methylated silica material, compared to ordinary and methylated silica materials, was investigated. Structural changes, such as decreased surface area and micropore volume, were more pronounced for the ordinary and methylated silica materials after hydrotreatment. In contrast, the cobalt-doped material exhibited higher resistance to these changes.</p> Graphical Abstract <p></p>