SURFACE-PROPERTIES AND HYDROCRACKING ACTIVITY OF NIMO ZEOLITE CATALYSTS

The hydrocracking properties of Ni, Mo and NiMo sulphides supported on an ultrastable HY zeolite were examined by studying the hydroconversi on of n-decane at moderate pressure (3 MPa). All catalysts were found to deactivate during the first hours on-stream, then reaching almost c onstant conversion values. Their cracking conversions are significantl y higher than that of the HY support. A strong imbalance between the h ydrogenation and the acidic function of catalysts was observed. The pr oduct selectivities did not depend on the conversion and the secondary cracking occurred. In the binary NiMo samples no synergetic effect be tween the individual Ni and Mo phases was observed. A reasonable corre lation between the n-decane steady-state conversions at 598 K, the sul phidation degree of the metals and Bronsted acidities of catalysts wer e found. (C) 1998 Elsevier Science B.V.