Spinel ferrites NiFeOsupported Ru catalysts have been prepared via a simple sol–gel route and applied for converting biomass-derived furfural to 2-methylfuran. The as-prepared catalysts were characterized by thermogr...Spinel ferrites NiFeOsupported Ru catalysts have been prepared via a simple sol–gel route and applied for converting biomass-derived furfural to 2-methylfuran. The as-prepared catalysts were characterized by thermogravimetric analysis（TG）, Nadsorption–desorption, X-ray diffraction（XRD）, scanning electronic microscopy（SEM）, and X-ray photoelectron spectroscopy（XPS）. Results showed that the catalysts had well-dispersed Ru active sites and large surface area for calcination temperature ranging from 300 to 500 ℃. The conversion of biomass-derived furfural into 2-methylfuran was conducted over Ru/NiFeOthrough catalytic transfer hydrogenation in liquid-phase with 2-propanol as the hydrogen source. A significantly enhanced activity and increased 2-methylfuran yield have been achieved in this study. Under mild conditions（180 ℃ and 2.1 MPa N）, the conversion of furfural exceeds 97% and 2-methylfuran yield was up to 83% over the catalyst containing 8 wt% Ru. After five repeated uses, the catalytic activity and the corresponding product yield remained almost unchanged. The excellent catalytic activity and recycling performance provide a broad prospects for various practical applications.展开更多
The elemental chemical state of NiFe2O4@TiO2 was changed by the reduction in order to investigate its effects on the photocatalytic performance.The synthesized NiFe2O4@TiO2 samples were characterized by means of X-ray...The elemental chemical state of NiFe2O4@TiO2 was changed by the reduction in order to investigate its effects on the photocatalytic performance.The synthesized NiFe2O4@TiO2 samples were characterized by means of X-ray diffraction (XRD),high-resolution transmission electron microscopy (HRTEM),Fourier-transform infrared spectroscopy (FT-IR),X-ray photoelectron spectroscopy (XPS),magnetic and photocatalytic measurements.Unexpectedly,the reduction reaction does not produce oxygen vacancies Ov and TiOx in the TiO2 lattice.The optimal catalyst was obtained at the reducing temperature of 800℃,and its degradation efficiency De to the methylene blue and reaction rate constant Kapp are the highest,reaching 99.9% and 3×10^-2 min-1,respectively.The reason could not be explained by both the visible light absorption and the appropriate amount of Ov and TiOx.Instead,the lowest ratios of TiOH and Ti-O-Fe(Ni) may be responsible for the optimum photocatalytic performance.展开更多
A comparative study on the corrosion resistance of NiFe_2O_4 ceramic inert anode for aluminum electrolysis prepared in the different sintering atmosphere was carried out in Na_3AlF_6-Al_2O_3 melt.The results show that...A comparative study on the corrosion resistance of NiFe_2O_4 ceramic inert anode for aluminum electrolysis prepared in the different sintering atmosphere was carried out in Na_3AlF_6-Al_2O_3 melt.The results show that the corrosion rates of NiFe_2O_4 ceramic inert anodes prepared in the vacuum and the atmosphere with oxygen content of 1×10^(-2) are 6.08 cm/a and 2.59 cm/a,respectively.A densification layer is formed at the surface of anode due to some reactions which produce aluminates.For the anode prepared in the atmosphere with oxygen content of 1×10^(-2),the thickness of the densification layer(about 50 μm) is thicker than that(about 20 μm) formed at the surface of anode prepared in the vacuum.The content of NiO and Fe(Ⅱ) in Ni(Ⅱ)x Fe(Ⅱ)1-x Fe(Ⅲ)_2O_4 increases with the decrease of the oxygen content of sintering atmosphere,which reduces the corrosion resistance of the material.展开更多
基金supported by the National Natural Science Foundation of China(21573031 and 21428301)the Fundamental Research Funds for the Central Universities(DUT15ZD106)
文摘Spinel ferrites NiFeOsupported Ru catalysts have been prepared via a simple sol–gel route and applied for converting biomass-derived furfural to 2-methylfuran. The as-prepared catalysts were characterized by thermogravimetric analysis（TG）, Nadsorption–desorption, X-ray diffraction（XRD）, scanning electronic microscopy（SEM）, and X-ray photoelectron spectroscopy（XPS）. Results showed that the catalysts had well-dispersed Ru active sites and large surface area for calcination temperature ranging from 300 to 500 ℃. The conversion of biomass-derived furfural into 2-methylfuran was conducted over Ru/NiFeOthrough catalytic transfer hydrogenation in liquid-phase with 2-propanol as the hydrogen source. A significantly enhanced activity and increased 2-methylfuran yield have been achieved in this study. Under mild conditions（180 ℃ and 2.1 MPa N）, the conversion of furfural exceeds 97% and 2-methylfuran yield was up to 83% over the catalyst containing 8 wt% Ru. After five repeated uses, the catalytic activity and the corresponding product yield remained almost unchanged. The excellent catalytic activity and recycling performance provide a broad prospects for various practical applications.
基金the Open Fund for Discipline Construction,Institute of Physical Science and Information Technology,Anhui Universitythe National Natural Science Foundation of China(No.51471001)。
文摘The elemental chemical state of NiFe2O4@TiO2 was changed by the reduction in order to investigate its effects on the photocatalytic performance.The synthesized NiFe2O4@TiO2 samples were characterized by means of X-ray diffraction (XRD),high-resolution transmission electron microscopy (HRTEM),Fourier-transform infrared spectroscopy (FT-IR),X-ray photoelectron spectroscopy (XPS),magnetic and photocatalytic measurements.Unexpectedly,the reduction reaction does not produce oxygen vacancies Ov and TiOx in the TiO2 lattice.The optimal catalyst was obtained at the reducing temperature of 800℃,and its degradation efficiency De to the methylene blue and reaction rate constant Kapp are the highest,reaching 99.9% and 3×10^-2 min-1,respectively.The reason could not be explained by both the visible light absorption and the appropriate amount of Ov and TiOx.Instead,the lowest ratios of TiOH and Ti-O-Fe(Ni) may be responsible for the optimum photocatalytic performance.
基金Projects(51474238,51334002)supported by the National Natural Science Foundation of China
文摘A comparative study on the corrosion resistance of NiFe_2O_4 ceramic inert anode for aluminum electrolysis prepared in the different sintering atmosphere was carried out in Na_3AlF_6-Al_2O_3 melt.The results show that the corrosion rates of NiFe_2O_4 ceramic inert anodes prepared in the vacuum and the atmosphere with oxygen content of 1×10^(-2) are 6.08 cm/a and 2.59 cm/a,respectively.A densification layer is formed at the surface of anode due to some reactions which produce aluminates.For the anode prepared in the atmosphere with oxygen content of 1×10^(-2),the thickness of the densification layer(about 50 μm) is thicker than that(about 20 μm) formed at the surface of anode prepared in the vacuum.The content of NiO and Fe(Ⅱ) in Ni(Ⅱ)x Fe(Ⅱ)1-x Fe(Ⅲ)_2O_4 increases with the decrease of the oxygen content of sintering atmosphere,which reduces the corrosion resistance of the material.
