NiMo catalysts supported on chromium modified zeolites of type X and Y - their structure and HDS activity

The paper reports results of a study on the performance and properties of N iMo catalysts supported on unmodified NaX and NaY zeolites and the same typ e of zeolites modified by exchange of Na+ ions into Cr3+ ones. Destruction of the zeolite crystal lattice is found to be much greater in the X-type th an in the Y-type zeolites. The zeolites impregnated with Mo6+ cations revea l higher hydrodesulfurization (HDS) activity than those modified only by Cr 3+ ions. The introduction of Ni2+ cations into the samples of Mo/NaCrX or M o/NaCrY almost always results in an enhanced HDS activity. (C) 2001 Elsevie r Science B.V. All rights reserved.