Synthesis of finely divided molybdenum sulfide nanoparticles in propylene carbonate solution
Résumé
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. Nanopartides of MoSx (x approximate to 4) of 10-30 nm 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 degrees C allows obtaining mesoporous MOS2 materials with very high pore volume and specific surface area, up to 0.45 cm(3)/g and 190 m(2)/g, respectively. The new materials show good potential for the application as unsupported hydrotreating catalysts. (C) 2014 Published by Elsevier Inc.