Liquid phase alkylation of anisole by benzyl alcohol catalyzed on alumina-supported niobia

The catalytic activity of Nb2O5, Al2O3 and alumina-supported niobia were evaluated in the alkylation reaction of anisole with benzyl alcohol in liquid phase. Alumina exhibited low activity and poor selectivity for alkylates. In contrast, high activities and selectivities to alkylated products were obtained with the niobia and niobia-alumina. The latter could be re-used after drying at 773 K. The catalysts were characterized by conventional techniques such as XRD, FTIR of adsorbed pyridine and nitrogen physisorption. Alumina presents only Lewis acidity, nevertheless niobium based catalysts present Brønsted and Lewis acid sites. The acidity trends are compatible with the activity patterns.