Tetralin hydrogenation catalyzed by Mo2C/Al2O3 and WC/Al2O3 in the presence of H2S

Supported molybdenum and tungsten carbides were synthesized by temperature-programmed reactions. These materials were characterized by XRD, EDS analysis, HRTEM and CO chemisorption. Hydrogenation of tetralin was carried out at a total pressure of 4 MPa (3.06 MPa of H-2), at 573 K, without or with sulfur (200 ppm of sulfur as DMDS). The resulting activities were compared with those of MoS2/Al2O3 and Pt (1% (w/w) metal loading) supported on Al2O3 or SiO2 In the absence of sulfur, WC/Al2O3 showed an initial activity similar to that of Pt/SiO2, higher than mat of MoS2/Al2O3 but lower than that of Pt/Al2O3. In the presence of H2S, WC/Al2O3 showed a steady-state activity similar to that of Pt/Al2O3 (which suffered a marked deactivation). Post-reaction characterization did not show any sulfur poisoning of the supported carbides. Therefore the supported carbides are sulfur-tolerant and promising catalysts for the hydrogenation of aromatics in diesel fuels in the presence of small amounts of S-containing compounds. (C) 2001 Elsevier Science B.V. All rights reserved.