The Y-Ni alloy is a primary precursor for the preparation of high-performance La-Y-Ni-based hydrogen storage materials.However,it cannot be produced continuously at low cost,which limits the wide popularization and ap...The Y-Ni alloy is a primary precursor for the preparation of high-performance La-Y-Ni-based hydrogen storage materials.However,it cannot be produced continuously at low cost,which limits the wide popularization and application of La-Y-Ni-based materials.In this paper,this problem was solved perfectly using electrochemical reduction of Y_ (2)O_(3)in the LiF-YF_(3)system.It is found that the reversible reduction from Y^(3+)to Y on the W electrode takes only one step,namely a significant soluble-soluble reaction controlled by Y^(3+)diffusion throughout the melt.Four typical signals of square wave voltammetry(SWV)corresponding to different kinds of Y-Ni intermetallic compounds are observed in LiF-YF_(3)and LiF-YF_(3)-Y_ (2)O_(3)melts,and reduction potential can become positive with the addition of Y_ (2)O_(3),probably because of the formation of more complexes in the melts.Homogeneous Y-Ni alloy samples were produced continuously and prepared via galvanostatic electrolysis by using bargain-price raw material(Y_ (2)O_(3))and setting the current density at 10 A/cm^(2)on the nickel electrode,before they were collected into a bottom receiver.A series of analyses including scanning electron microscopy-energy idspersive X-ray spectroscopy(SEM-EDS),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and inductively coupled plasma mass spectrometry(ICP-MS),demonstrate that concentration of yttrium in Y-Ni alloy is adjustable within the wide range of 44 wt%to 72 wt%by fine-tuning the electrolysis temperature(875-1060℃)in the LiF-YF_(3)system to ensure the optimal hydrogen storage performance and economic efficiency of La-Y-Ni-based hydrogen-storage materials.展开更多
基金Project supported by the State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization(2020Z2132)Ganjiang Innovation Academy,Chinese Academy of Sciences(E055C002)。
文摘The Y-Ni alloy is a primary precursor for the preparation of high-performance La-Y-Ni-based hydrogen storage materials.However,it cannot be produced continuously at low cost,which limits the wide popularization and application of La-Y-Ni-based materials.In this paper,this problem was solved perfectly using electrochemical reduction of Y_ (2)O_(3)in the LiF-YF_(3)system.It is found that the reversible reduction from Y^(3+)to Y on the W electrode takes only one step,namely a significant soluble-soluble reaction controlled by Y^(3+)diffusion throughout the melt.Four typical signals of square wave voltammetry(SWV)corresponding to different kinds of Y-Ni intermetallic compounds are observed in LiF-YF_(3)and LiF-YF_(3)-Y_ (2)O_(3)melts,and reduction potential can become positive with the addition of Y_ (2)O_(3),probably because of the formation of more complexes in the melts.Homogeneous Y-Ni alloy samples were produced continuously and prepared via galvanostatic electrolysis by using bargain-price raw material(Y_ (2)O_(3))and setting the current density at 10 A/cm^(2)on the nickel electrode,before they were collected into a bottom receiver.A series of analyses including scanning electron microscopy-energy idspersive X-ray spectroscopy(SEM-EDS),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and inductively coupled plasma mass spectrometry(ICP-MS),demonstrate that concentration of yttrium in Y-Ni alloy is adjustable within the wide range of 44 wt%to 72 wt%by fine-tuning the electrolysis temperature(875-1060℃)in the LiF-YF_(3)system to ensure the optimal hydrogen storage performance and economic efficiency of La-Y-Ni-based hydrogen-storage materials.
