Acidity and Catalytic Behavior of Substituted MCM-48

Tertiary butylation of phenol over mesoporous MeMCM-48 and MeMCM-41 (Me = Ga, Fe, Al or B) solid acid catalysts

“…However, much attention has been devoted on the catalytic properties of metal-containing MCM-41 structure, but only very little attention has been paid on the catalytic properties of metal-incorporating MCM-48 materials [7][8][9][10], probably because of the difficulties to synthesize good quality samples because of the narrower homogeneity region of the MCM-48 phase [11]. On the other hand, with the inherent benefit of a three-dimensional pore structure, as well as the associated advantage of the resistance against pore blockage, MCM-48 could serve as an excellent candidate for catalytic applications [7,[12][13][14][15][16][17][18].…”

Synthesis of MCM-48 with a high thermal and hydro-thermal stability

“…MCM-48, one member of these new materials contains two independent three-dimensional pore systems, which are interwoven and situated in a mirror-plane position to each other [4]. This special pore system provides favorable mass transfer kinetics in catalytic and separation applications than MCM-41 with a one-dimensional hexagonal directional pore system.…”

Self-assembled materials for catalysis

“…This can be attributed to the existence of larger pores and interconnected small pores in SBA-15, which facilitate the mass transfer and therefore promote both conversion and selectivity [48 54]. For Al-, Ga-, and Fe-substituted MCM-48 used as catalyst for acetone conversion, the majority of active sites are weak to medium acid sites, while a minority of strong acid sites co-exist, which may be the reason for the observed low selectivity [52]. In addition to in situ and post-synthetic grafting methods for the introduction of Al into the matrix of mesoporous silica, supercritical fl uids (CO 2 or propane) have also been employed to enhance the interaction between Al and silica walls inside the channels since this leads to a highly thermally and hydrothermally stable Al-MCM-41 material [55].…”