Catalytic hydroconversion of lignite-related model compounds over difunctional Ni-Mg2Si/γ-Al2O3

Catalysts Ni/γ-Al 2 O 3 , Mg 2 Si/γ-Al 2 O 3 , and Ni-Mg 2 Si/γ-Al 2 O 3 were prepared. Their activities for catalytic hydroconversions (CHCs) of some lignite-related model compounds were examined. For the CHCs of oxydibenzene (ODB), benzyloxybenzene, and oxybis(methylene)dibenzene, the suitable loadings of Ni and Mg 2 Si are 33 and 20% in Ni-Mg 2 Si/γ-Al 2 O 3 , respectively, and the optimal reaction conditions are 4   MPa of initial hydrogen pressure, 240   °C, and 2   h, under which ODB was almost completely converted to cyclohexane. The formation of possible intermediates during the CHC of ODB was discussed. Ni-Mg 2 Si/γ-Al 2 O 3 was proposed to have 3 functions, i.e., activating H 2 to biatomic active hydrogen (H⋯H), releasing H − , and heterolytically splitting H⋯H to release H − as well, resulting in the hydrogenation of aromatic rings and the hydrocracking of C O bonds, respectively.