NiB/SiO2 amorphous alloy catalyst was prepared by power electroless plating method and characterized by induction coupled plasma(ICP),Brunauer–Emmett–Teller method(BET),transmission electron microscope(TEM)and X-ray...NiB/SiO2 amorphous alloy catalyst was prepared by power electroless plating method and characterized by induction coupled plasma(ICP),Brunauer–Emmett–Teller method(BET),transmission electron microscope(TEM)and X-ray diffraction(XRD)techniques.The catalytic perfor-mance of NiB/SiO2 was investigated for the hydrogenation of furfuryl alcohol(FA)to tetrahydrofurfuryl alcohol(THFA).The effects of operational conditions,such as reaction tem-perature,pressure,and stirring rate were carefully studied.The proper conditions were determined as the following:pressure 2.0 MPa,temperature 120°C and stirring rate 550 r/min.A typical result with FA conversion of 99%and THFA selectivity of 100%was obtained under such conditions,which was close to that over Raney Ni.展开更多
Phenylalanine (Phe) is a significant amino acid that cannot be synthesized by human themselves but must be taken from environment. It was initially found that the nanosized amorphous Ni-B/SiO2 alloy prepared by the ...Phenylalanine (Phe) is a significant amino acid that cannot be synthesized by human themselves but must be taken from environment. It was initially found that the nanosized amorphous Ni-B/SiO2 alloy prepared by the chemical reduction method was an effective catalyst for the preparation of Phe from phenylpyruvic acid (PPA) by amination and hydrogenation. It has been found that the amorphous Ni-B/SiO2 alloy catalyst exhibits superior activity and selectivity to the traditional catalysts Raney Ni and Urushibara nickel. The effects of reaction time, amounts of catalysts and ammonia solution, reaction temperature, and H2 pressure on the reaction have been investigated systematically. The results indicated that the yield of Phe was 97.9%, and the selectivity for Phe reached 98.9% when the reaction was carried out for 3 h at 333 K and 2.0 MPa of H2 with m(Cat.) : m(PPA) = 0.6 : 1.0 and n(NH3) : n(PPA) = 3 : 1. The catalysts were characterized by XRD, AAS, XPS, BET, and TEM, and the relationship between the catalyst structure and the catalytic activity was discussed in detail. It was found that the reason why Ni-B/SiO2 amorphous alloy catalyst was much more active for the preparation of Phe could be accounted for by the presence of electron-rich Ni due to electron donation from alloying B; the smaller size of Ni-B particles, the larger specific surface area of Ni-B/SiO2.展开更多
文摘NiB/SiO2 amorphous alloy catalyst was prepared by power electroless plating method and characterized by induction coupled plasma(ICP),Brunauer–Emmett–Teller method(BET),transmission electron microscope(TEM)and X-ray diffraction(XRD)techniques.The catalytic perfor-mance of NiB/SiO2 was investigated for the hydrogenation of furfuryl alcohol(FA)to tetrahydrofurfuryl alcohol(THFA).The effects of operational conditions,such as reaction tem-perature,pressure,and stirring rate were carefully studied.The proper conditions were determined as the following:pressure 2.0 MPa,temperature 120°C and stirring rate 550 r/min.A typical result with FA conversion of 99%and THFA selectivity of 100%was obtained under such conditions,which was close to that over Raney Ni.
基金Fundamental research project of South-Central University for Nationalities (No. YZZ05010)
文摘Phenylalanine (Phe) is a significant amino acid that cannot be synthesized by human themselves but must be taken from environment. It was initially found that the nanosized amorphous Ni-B/SiO2 alloy prepared by the chemical reduction method was an effective catalyst for the preparation of Phe from phenylpyruvic acid (PPA) by amination and hydrogenation. It has been found that the amorphous Ni-B/SiO2 alloy catalyst exhibits superior activity and selectivity to the traditional catalysts Raney Ni and Urushibara nickel. The effects of reaction time, amounts of catalysts and ammonia solution, reaction temperature, and H2 pressure on the reaction have been investigated systematically. The results indicated that the yield of Phe was 97.9%, and the selectivity for Phe reached 98.9% when the reaction was carried out for 3 h at 333 K and 2.0 MPa of H2 with m(Cat.) : m(PPA) = 0.6 : 1.0 and n(NH3) : n(PPA) = 3 : 1. The catalysts were characterized by XRD, AAS, XPS, BET, and TEM, and the relationship between the catalyst structure and the catalytic activity was discussed in detail. It was found that the reason why Ni-B/SiO2 amorphous alloy catalyst was much more active for the preparation of Phe could be accounted for by the presence of electron-rich Ni due to electron donation from alloying B; the smaller size of Ni-B particles, the larger specific surface area of Ni-B/SiO2.