Amorphous Ni B/SiO2 catalysts were prepared by chemical reduction of Ni2＋with KBH4.ICP was used to analyze the composition of alloys.XRD,TEM,SAED and HREM were used to examine the structures of samples fresh and afte...Amorphous Ni B/SiO2 catalysts were prepared by chemical reduction of Ni2＋with KBH4.ICP was used to analyze the composition of alloys.XRD,TEM,SAED and HREM were used to examine the structures of samples fresh and after thermal treatment in different atmospheres.The results indicated that the supported NiB has a higher structural stability than ultrafine NiB amorphous alloy.Low temperature pretreatment in hydrogen can reduce nickel oxide on the surface of catalysts.However,treatment in hydrogen is more favorable than in atmosphere and nitrogen for keeping it in stable state.展开更多
Amorphous Ni B/γ Al 2O 3 catalyst 1 is prepared with chemical reduction by KBH 4 solution after wetness impregnation and desiccation at 70 ℃ first and then at 110 ℃ for thorough water removal. Its higher catalytic ...Amorphous Ni B/γ Al 2O 3 catalyst 1 is prepared with chemical reduction by KBH 4 solution after wetness impregnation and desiccation at 70 ℃ first and then at 110 ℃ for thorough water removal. Its higher catalytic activity than amorphous Ni B/γ Al 2O 3 catalyst 2, prepared by conventional one step desiccation procedure at 110 ℃, is identified in liquid phase benzene hydrogenation to cyclohexane. Both catalysts are characterized by XRD and SEM, Ni B/γ Al 2O 3 catalyst 1 has a higher active specific surface area and dispersion degree, which can be assigned to more effective distribution of nickel salt over the support during desiccation, thus resulting in its superior activity in benzene hydrogenation.展开更多
文摘Amorphous Ni B/SiO2 catalysts were prepared by chemical reduction of Ni2＋with KBH4.ICP was used to analyze the composition of alloys.XRD,TEM,SAED and HREM were used to examine the structures of samples fresh and after thermal treatment in different atmospheres.The results indicated that the supported NiB has a higher structural stability than ultrafine NiB amorphous alloy.Low temperature pretreatment in hydrogen can reduce nickel oxide on the surface of catalysts.However,treatment in hydrogen is more favorable than in atmosphere and nitrogen for keeping it in stable state.
文摘Amorphous Ni B/γ Al 2O 3 catalyst 1 is prepared with chemical reduction by KBH 4 solution after wetness impregnation and desiccation at 70 ℃ first and then at 110 ℃ for thorough water removal. Its higher catalytic activity than amorphous Ni B/γ Al 2O 3 catalyst 2, prepared by conventional one step desiccation procedure at 110 ℃, is identified in liquid phase benzene hydrogenation to cyclohexane. Both catalysts are characterized by XRD and SEM, Ni B/γ Al 2O 3 catalyst 1 has a higher active specific surface area and dispersion degree, which can be assigned to more effective distribution of nickel salt over the support during desiccation, thus resulting in its superior activity in benzene hydrogenation.
