Selective ring-opening (RO) of decalin over the catalysts comprising of Pt-Ir and Ni-Mo carbide supported on HY and Hbeta was compared in a trickle bed reactor. The catalysts were synthesized by incipient wetness impregnation method and characterized by elemental analysis, BET surface area measurement, XRD,TPR and TPD of ammonia. XRD of the carbide catalysts showed no bulk molybdenum peaks and the structure did not collapse in the carburization process. TPD of ammonia showed a large amount of acidic sites on the HY-supported Pt-Ir and Ni-Mo carbide catalysts. The HY-supported Pt-Ir and Ni-Mo carbide catalysts showed higher RO activity and RO products selectivity than the corresponding Hbeta catalysts. The activity and selectivity of the Pt-Ir catalysts on H-Y are greater than Hbeta. A maximum RO yield of 33.5% was observed with the HY-supported Ni-Mo carbide catalyst. The yield and selectivity with the carbide catalysts supported on, HY are comparable with that of HY-supported noble metal catalysts. (C) 2009 Elsevier B.V. All rights reserved.