Synthesis of finely divided molybdenum sulfide nanoparticles in propylene carbonate solution

Abstract

Molybdenum sulfide nanoparticles have been prepared from the reflux solution reaction involving ammonium heptamolybdate and elemental sulfur in propylene carbonate. Addition to the reaction mixture of starch as a natural capping agent leads to lesser agglomeration and smaller size of the particles. Nanoparticles of MoSx (x≈4) of 10–30nm size are highly divided and form stable colloidal suspensions in organic solvents. Mo K edge EXAFS of the amorphous materials shows rapid exchange of oxygen to sulfur in the molybdenum coordination sphere during the solution reaction. Thermal treatment of the amorphous sulfides MoSx under nitrogen or hydrogen flow at 400°C allows obtaining mesoporous MoS2 materials with very high pore volume and specific surface area, up to 0.45cm3/g and 190m2/g, respectively. The new materials show good potential for the application as unsupported hydrotreating catalysts.