Synthesis and Reactivity of Al-MMM-2: A New Microporous/Mesoporous Catalyst for the Alkylation of Toluene

Porous, mixed-phase aluminosilicate materials containing a microporous MFI phase and a mesoporous Al-MCM-48 phase were synthesized using a one-pot synthesis method. Initially, the gemini surfactant “18-12-18” was used to form Al-MCM-48, and then the MFI template tetrapropylammonium (TPA+) was added to the reaction mixture at a later time. Subsequent crystallization at 150 °C led to the formation of a series of mixed-phase materials. These new materials, called “Al-MMM-2” (microporous/mesoporous materials), were characterized using powder X-ray diffraction and 29Si MAS-NMR. Consistent with previous results, the amount of the microporous phase formed was dependent on the crystallization time; thus, a range of materials could be formed from a single reaction mixture. In the alkylation of toluene with benzyl alcohol, Al-MMM-2 materials showed greater structural stability, catalytic activity, and product selectivity during repeated reaction cycles, compared to either pure Al-MCM-48 or pure MFI.