Based CoMo sulphided catalysts supported on hydroxyapatite: Dimethyldisulphide (DMDS) hydrogenolysis

Abstract A series of Ca-deficient and Co-containing hydroxyapatite samples, noted A r and C x , respectively, where r is the total Ca/P molar ratio ( r =1.46–1.62) and x the Co wt%, were prepared by precipitation in aqueous media. The catalytic activities of CoMo/A r and Mo/C x sulphided catalysts have been examined for the S–S bond hydrogenolysis of dimethyldisulphide (DMDS) under relatively mild operating conditions (200°C, 1 atm). The overall activity depends on the Co depositing mode and the hydroxyapatite carrier Ca/P molar ratio. Depositing Co by impregnation on hydroxyapatite samples with low Ca/P molar ratios involves an increase of the catalytic activity until approaching that corresponding to CoMo/Al 2 O 3 catalyst. This can be attributed probably to a better dispersion of the CoMo sulphided catalysts on apatitic carrier with low Ca/P molar ratios. DMDS is selectively reduced to CH 3 SH on the CoMo/ A 1,46 sulphided catalyst than on the CoMo/Al 2 O 3 one, even at conversions as higher as 100%.