Ring Opening of Decalin Over Zeolite-Supported Iridium Catalysts

Selective ring opening of decalin was investigated over various metal-modified zeolites in order to shed light on the key parameters affecting the selectivity to ring-opening products at low extent of cracking reactions. Ir-modified zeolites H-Y and H-Beta having different concentration and strength of acid sites were studied in a batch reactor at 250-310 A degrees C and 20-60 bar H(2) and their performance was compared with that of Pt-modified zeolites. The concentration of Bronsted acid sites, reaction temperature and hydrogen pressure were shown to be the crucial reaction parameters. To obtain high selectivity to formation of ring-opening products from decalin, mildly acidic Ir-modified Beta was the best choice when the reaction was carried out at temperature of 270 A degrees C or lower and at H(2) pressure of 60 bar. Under these conditions the selectivity and yield of ring-opening products exceeded 65 and 60%, respectively.