Figure 9
Representation of the proposed species involved during the in situ sulfurization of the freshly calcined Co–Mo/Al2O3 and Co–Ni–Mo/Al2O3. The oxide precursor was identified as octahedral Co2+ and Co3+. Prior to the complete sulfided state, cobalt oxy-sulfide intermediate species are formed. At 400°C there are two possible reaction pathways that result in either the catalytic active Co2+ (C4v) sulfide species or the bulk Co2+ (Oh) sulfide species. |