Novel efficient synthesis of beta-naphthyl methyl ether using sulfated mesoporous molecular sieve Al-MCM-41

The mesoporous molecular sieve Al-MCM-41 and sulfated Al-MCM-41 were prepar ed and characterized with various techniques: XRD, ICP-AES, BET, Al-27 and Si-29 MAS-NMR, FTIR, TPD of ammonia and N-2 adsorption isotherms. Impregnat ion of Al-MCM-41 with sulfuric acid results in the decrease of crystallinit y, surface area, pore volume and the expelling of aluminum from the AI-MCM- 41 framework, with concomitant increase of the Lewis acidity. P-Naphthyl me thyl ether was synthesized from P-naphthol and methanol at 200 degrees C an d 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, gamma-alumina, USY and H-ZSM-5 zeolites. T he sulfated AI-MCM-41 catalyst forms the exclusive product of beta-naphthyl methyl ether and has much higher yields than other catalysts except USY. T he non-framework aluminum existing in the intrachannel space of Al-MCM-41 p robably causes the enhancement of catalyst activity. The catalytic results are correlated to the acidity, the surface area and the pore size of the ca talysts. (C) 1999 Elsevier Science B.V. All rights reserved.