Stability and textural properties of cobalt incorporated MCM-48 mesoporous molecular sieve

Transition metal cobalt incorporated MCM-48 mesoporous molecular sieves (CoMCM-48) with different Co contents were synthesized hydrothermally at 120 °C for 24 h by directly adding fluoride ions to the initial gel. The resulting materials were characterized by means of XRD, TEM, FT–IR, UV–vis, TPR and N2 physical adsorption, respectively. The effect of various factors, such as the Si/Co molar ratio, calcination temperature and hydrothermal treatment time, on the crystalline structure and textural properties of CoMCM-48 was investigated in detail. The results show that the CoMCM-48 mesoporous materials with high specific surface area were successfully synthesized. A small amount substitution of Co for Si in MCM-48 did not significantly change the textural properties while the higher cobalt incorporated leads to decrease of the surface area and deterioration of structural regularity. Furthermore, the resulting CoMCM-48 still retained the cubic mesoporous framework even after calcination at 800 °C for 4 h or hydrothermal treatment at 100 °C for 24 h.