Sulfide catalysts made of cobalt and hydroxyapatite

We have prepared a series of catalysts combining cobalt and a hydroxyapatit e by coprecipitation in a basic medium. These sulfided solids catalyse the hydrodesulfurization of dimethyldisulfide at 360 degrees C and its hydrogen olyzis into CH3SH at 200 degrees C. The coprecipitated solids are found mor e active than the impregnated catalysts because they exhibit a better dispe rsion of the active Co-S phase at higher Co content. With the precipitated catalysts, Co ions substitute for Ca ions into the apatite structure, The f ormation of large sulfide particles is thus more difficult as a result of s ulfiding because the Co ions have to move to the surface. The apatite catal ysts are intrinsically. as active as their homologous Co/Al2O3.