STUDY ON SILICA-SUPPORTED CU-CR-MO NITROBENZENE HYDROGENATION CATALYSTS

The effect on the life time behavior of nitrobenzene hydrogenation of the addition of Cr and Mo-oxide to a Cu/SiO2 catalysts was studied in a fixed-bed flow reactor and the results were analyzed in terms of cha nge of the surface species studied by Auger and XPS spectroscopes, cha nge of reducibility behavior was studied by H-2-TPR and change in the crystalline phases was studied by XRD. The results indicate that the s tability of catalysts modified by Cr-and Mo-oxide is improved remarkab ly; the Cr2O3 as well as the MoO3 in catalysts has the effect of elect ron donor to Cu; and proper contents of Cr, Mo in catalysts can increa se the dispersity of Cu particles. (C) 1997 Elsevier Science B.V.