PREPARATION OF MOS2 CATALYSTS BY IN-SITU DECOMPOSITION OF TETRAALKYLAMMONIUM THIOMOLYBDATES

Molybdenum tetraalkylammonium thiosalts were used as precursors for th e in situ formation of MoS2 catalysts for dibenzothiophene hydrodesulf urization. The influence of the chemical composition of precursors (R4 N)(2)MoS4 With R=H+, CH3+ or C4H9+ and mechanical pressing of precurso rs on the composition and activity of prepared catalysts was investiga ted. The change of cation from proton to methyl- and to butylammonium increased the surface area and HDS activity of MoS2 catalysts. Extreme ly high surface area surpassing 200 m(2)/g was obtained for catalysts formed from tetrabutylammonium thiomolybdate. Significant difference w as observed for pattern of thermal decomposition of alkylammonium thio salts compared to ammonium ones. Unusual sponge-like morphology by rea son of appearance of secondary porosity was observed in the case of te trabutylammonium precursors. (C) 1998 Elsevier Science B.V. All rights reserved.