Novel efficient synthesis of β-naphthyl methyl ether using sulfated mesoporous molecular sieve Al-MCM-41 Original Research Article

The mesoporous molecular sieve Al-MCM-41 and sulfated Al-MCM-41 were prepared and characterized with various techniques: XRD, ICP–AES, BET, 27Al and 29Si MAS–NMR, FTIR, TPD of ammonia and N2 adsorption isotherms. Impregnation of Al-MCM-41 with sulfuric acid results in the decrease of crystallinity, surface area, pore volume and the expelling of aluminum from the Al-MCM-41 framework, with concomitant increase of the Lewis acidity. β-Naphthyl methyl ether was synthesized from β-naphthol and methanol at 200°C and 35 bar over Al-MCM-41 and sulfated Al-MCM-41 in a batch autoclave reactor. The catalytic results were compared with those obtained by using sulfuric acid, amorphous silica–alumina, γ-alumina, USY and H-ZSM-5 zeolites. The sulfated Al-MCM-41 catalyst forms the exclusive product of β-naphthyl methyl ether and has much higher yields than other catalysts except USY. The non-framework aluminum existing in the intrachannel space of Al-MCM-41 probably causes the enhancement of catalyst activity. The catalytic results are correlated to the acidity, the surface area and the pore size of the catalysts.