Preparation and activity evaluation of NiMoFeB/γ-Al_2O_3 catalyst

MoNiFeB/γ/-Al_2O_3 amorphous alloy catalysts were prepared by NaBH_4 reduction after impregnating NiCl_2·6H_2O,(NH_4)_6Mo_7O_(24)·4H_2O and FeCl_3·6H_2O on γ-Al_2O_3.The activity of MoNiFeB/ γ/-Al_2O_3 was investigated using liquid-phase hydrogenation of furfural as a probe reaction.The results showed that the hydrogenation activity and selectivity of NiMoFeB/γ/-Al_2O_3 were higher than that of NiMoB/ γ/-Al_2O_3;after reaction for 3.0 h at 60 ℃ and 5.0 MPa in methanol,furfural conversion reached nearly 100%.Effects of Fe doping amount and impregnation sequence of the activity component on catalytic activity were studied.The optimum atom ratio of Ni + Mo to Fe was 20:1.Impregnation sequence of the precursor salts of Ni,Mo and Fe had significant effects on catalytic activities of as-prepared catalysts. NiMoFeB/γ/-Al_2O_3 prepared by simultaneous impregnation of Ni,Mo and Fe salts exhibited the highest catalytic activity.XRD patterns indicated that the as-prepared catalyst possessed amorphous structure with relative high dispersion of activity component and thermal stability.