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Two series of Ni-Mo catalysts were prepared using Al2O3 and TiO2 supports. Ni/ (Ni+Mo) ratio of the catalysts was varied, while a total metal loading of Ni and Mo was kept constant. Sulfiding conditions were optimized to give superior catalytic activities. After sulfiding, model test reactions were carried out to evaluate hydrogenation (HY), hydrocracking (HC) and hydrodesulfurization (HDS) activities of the sulfide catalysts.The highest HY activities of Al2O3 and TiO2 supported catalysts were obtained when the Ni/ (Ni+Mo) ratios were 0.25 and 0.12, respectively, showing different interaction between support and active metals. XPS measurements revealed that the atomic ratio of active metal sulfide {NiS/ (NiS+MoS2)}, which gave the highest HY activities, was 0.2 on both supports. This indicates that sulfided active metals such as NiS or MoS2 play an important role for the formation of HY active sites.Both catalysts supported on Al2O3 and TiO2 showed the highest HDS activities when the NiS/ (NiS+MoS2) ratio was 0.4. This ratio is different from that obtained in HY measurements. While HC activities of the two series of sulfide catalysts decreased with increasing of Ni loading.These results clealy show that HY, HC and HDS active sites of Ni-Mo sulfide catalysts are different each other and that proper selection of each active metal loading is required for preparing highly selective catalysts.

反応原料中の硫黄化合物が硫化物触媒の核水素化 (HY) 活性と水素化分解 (HC) 活性に与える影響について検討を行った。硫化物触媒のHY活性の序列は, 反応中に硫黄化合物が存在しない場合Ni-W>Ni-Mo≫Co-Moであったが, Ni-WおよびNi-Mo触媒は反応中に硫黄化合物が存在すると, HY活性サイトが大幅に低下することがモデル反応の結果, 明らかとなった。助触媒であるNiとCoを比較した場合, Niは高いHY活性を与えるが硫黄化合物による被毒も大きいことがわかった。一方, HC活性は硫黄化合物が存在するとむしろ向上することが明らかとなり, 新しいHC活性サイトの形成が示唆された。

CANMETプロセスより得られたコプロセシングオイルの灯•軽油留分についてアップグレーディング反応のあり方, およびその触媒についての検討を行った。灯•軽油留分からガソリン留分への軽質化反応は一段の反応では進行せず, 芳香環の水素化および脱ヘテロからなる第一段アップグレーディング反応と水素化されたナフテン環の開裂を行う第二段アップグレーディング反応の組み合わせが必要なことが明らかになった。アップグレーディング反応に二段階反応, 第一段反応にNi-Mo/Al2O3触媒, 第二段反応にNi-W/USY-Al2O3触媒を用いることによりコプロセシングオイルの灯•軽油留分から効率よくガソリン留分を得ることができた。また, 二段階反応によりトータルの脱ヘテロ効率も大幅に向上した。

Ni promoter effect on the structure and the sulfiding state of Mo phase in Ni-Mo/Al2O3 catalysts were studied using Temperature Programmed Sulfiding (TPS) and XAFS. The results for TPS and Mo-K edge EXAFS suggest that Ni addition promotes the sulfiding of Mo phase and the growth of MoS2-like species in the horizontal direction. Ni-K edge XAFS results for sulfided catalysts show that most of Ni atoms may exist as oxidic state.

Molybdenum sulfide catalysts supported on crystalline CoO·Al2O3 spinel showed much higher hydrocracking activity of C–C bonds and lower hydrogenation activity of aromatic rings than those other supports. Superior HDS activity of the catalyst was obtained on this new type of crystalline supports.