Modification of the Pd/SiO2-Al2O3 catalyst's thioresistance by the addition of a second metal (Pt, Ru, and Ni)

The thioresistance of amorphous silica-alumina (ASA)-supported Pd catalyst was modified by the incorporation of a second metal (Pt, Ru or Ni). The catalysts were studied in the dibenzothiophene (DBT) hydrodesulfurization (HDS) at P = 5 MPa, T = 473-588 K and WHSV = 0.48 h(-1). The HDS conversions at steady state followed the sequence: Pt-Pd > Pd > 8Ni-Pd > Ru-Pd > 4Ni-Pd. The Pt-Pd catalyst was found to be the only one which did not show deactivation during on-steam operation. The factors influencing catalyst thioresistance are discussed. (C) 2004 Elsevier B.V. All rights reserved.