Two series of Ni-Mo catalysts were prepared using an impregnation method. In each series Ni/ (Ni+Mo) ratio of the catalysts was varied, while a total met-al loading of Ni and Mo was kept constant (9.9 and 17wt% as MoO₃). Sulfiding conditions were varied to give superior catalytic activities. After was sulfiding, model test reactions were carried out to evaluate hydrogenation (HY), hydrocracking (HC) and hydrodesulfurization (HDS) activities of the sulfide catalysts.
The highest HY and HDS activities of the Ni-Mo catalysts were obtained when the Ni/ (Ni+Mo) ratios were 0.3-0.4 and 0.4-0.5 respectively, showing that HY and HDS active sites are different. HC activities decreased with increasing of Ni loading. Similar trends were observed when the total active metal loading was increased from 9.9 to 17wt% as MoO₃. While considerable enhancements in HY, HC and HDS activities were observed on the catalysts with high metal loadings.
XPS measurements revealed that atomic ratios of active metal sulfide
{NiS/ (NiS+MoS₂)}, which gave the highest HY and HDS activities, were different from those of Ni/ (Ni+Mo). This is mainly due to the different sulfiding behavior between Ni and Mo.
HDS activities increased with increasing of metal sulfiding followed by saturation. However, the catalysts, sulfided at higher temperature, showed lower HDS activities, though metal sulfidings were promoted to some extent. This is probably due to sinter-ing of the active metals, resulting in the decrease of HDS active sites.

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Proton Donor Quality Index (PDQI) was calculated from the chemical structural analyses by means of GC-LVEI MS for an SRC-II heavy distillate and twelve hydrogenated coal liquids derived from it. Evaluation of hydrogen donor ability of the liquids was attempted. PDQI increased with increasing severity of hydrogenation at the temperature less than 420°C, but PDQI decreased over 430°C. PDQI at 460°C became smaller than that of SRC-II heavy distillate.
Liquefaction experiments with Akabira coal were carried out using the liquids as solvent. It was found that the coal conversions increased with the increase of PDQI of the solvents. Multi regression analyses between the coal conversions and PDQI of the chemical species in the solvents were performed, and the role of the species for the coal conversions was estimated. And then, a relationship between benzene soluble conversions and PDQIs fitted by those results in the experiments of Akabira coal liquefaction with recycling solvents was discussed.

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