Selective liquid-phase transformation of α-pinene over dealuminated mordenites and Y-zeolites Original Research Article

Dealuminated mordenite (MOR) and faujasite (FAU) zeolites, and a 13% alumina amorphous aluminosilicate were tested as catalysts for the liquid-phase transformation of α-pinene at 120°C in a batch reactor. Limonene and camphene were the main products observed over zeolites. Mordenites gave the maximum yield (68%) of limonene and camphene with a selectivity of camphene/(limonene+camphene) greater than 0.54. Wider pore diameters and larger pore volumes gave higher yields of undesired products, probably sesquiterpenes and other heavy compounds. The amorphous aluminosilicate selectivity to camphene+limonene was the poorest (18%) and gave the highest yield of undesired products (48%). The specific transformation rate of α-pinene passes through a maximum at 0.4 AlIV per 1000 Å3 of unit cell, corresponding to 1 AlIV/MOR unit cell or 6 AlIV/FAU unit cell.