In order to develop a new sulfur-tolerant noble metal catalyst with significantly increased catalytic activity for aromatic hydrogenation, the screening tests of the various non-zeolitic noble metal catalysts were carried out with hydrotreated light cycle oil (LCO)/straight-run light gas oil (SRLGO) feed containing 32-34 vol% aromatics and 172-474 ppm sulfur at a temperature of 573 K, hydrogen pressure of 4.9 MPa, and LHSV of 1.5 h(-1). The Pt-Pd/SiO(2)-Al(2)O(3) catalyst was the most highly active catalyst for aromatic hydrogenation under the conditions applied. The co-existence of Pt with Pd on SiO(2)-Al(2)O(3) remarkably enhanced the catalytic activity, which depended on the Pd/(Pt + Pd) weight ratio and reached a maximum of about 0.7 Pd/(Pt + Pd) weight ratio. Furthermore, the long-term stability test under industrial operating conditions demonstrated the excellent stability of the Pd-Pd/SiO(2)-Al(2)O(3) catalyst. (C) 2000 Elsevier Science B.V. All rights reserved.
