Nanostructured Mg–Ni alloy with the particle size in the range of 40–50 nm was synthesized by the thermal decomposition of bipyridyl complexes of Mg and Ni metals at 773 K for 24 h under dry argon gas ambient. The a...Nanostructured Mg–Ni alloy with the particle size in the range of 40–50 nm was synthesized by the thermal decomposition of bipyridyl complexes of Mg and Ni metals at 773 K for 24 h under dry argon gas ambient. The as-prepared nano-alloy was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） for compositional and structural analysis. The alloy exhibited superior hydrogen absorption and desorption behavior with 3.2 wt% absorption within 1 min at 573 K and about 3 wt% desorption within 5–10 min at 573 K. This favorable behavior of Mg–Ni compound for the hydrogen storage is due to the specific nanostructure of the material. The low activation energy values and favorable thermodynamics indicate that the prepared Mg–Ni alloy is an attracting material for hydrogen storage applications.展开更多
This study investigates the effect of Ce content on the hydrogen storage properties of Ti_(0.98)Zr_(0.02)Mn_(1.5)Cr_(0.05)V_(0.43)Fe_(0.09)Ce_(x)(x=0,0.02,0.04,and 0.06,at%)alloys.Microstructural analysis of these all...This study investigates the effect of Ce content on the hydrogen storage properties of Ti_(0.98)Zr_(0.02)Mn_(1.5)Cr_(0.05)V_(0.43)Fe_(0.09)Ce_(x)(x=0,0.02,0.04,and 0.06,at%)alloys.Microstructural analysis of these alloys revealed dendritic microstructures without the segregation of chemical elements,with the C14 Laves phase identified as the dominant phase.After two activation cycles at 4 MPa and 293 K,the alloys exhibited excellent hydrogen absorption properties.The addition of Ce significantly improved the kinetics of the alloys.At x=0.02,the hydrogen absorption capacity reached 90%of its maximum within 137 s at 293 K.Pressure-composition-temperature curves indicated that hydrogen absorption capacity initially increased first and then decreased with increasing Ce content,reaching a maximum value of 1.85wt%at x=0.04.Thermodynamic results demonstrated that the enthalpy and entropy of hydrogen absorption followed a similar trend,which was consistent with the variation in hydrogen storage capacity.Thus,the improvement in hydrogen absorption capacity due to the addition of Ce is attributed to the increase in enthalpy.The increase of the lattice constant in the C14 Laves phase and the deoxidization effect of Ce are expected to be beneficial for the improvement of hydrogen absorption kinetics.展开更多
基金supported by Higher Education Commission (HEC), Islamabad, Pakistan under PhD indigenous-5000 Fellowship Program
文摘Nanostructured Mg–Ni alloy with the particle size in the range of 40–50 nm was synthesized by the thermal decomposition of bipyridyl complexes of Mg and Ni metals at 773 K for 24 h under dry argon gas ambient. The as-prepared nano-alloy was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） for compositional and structural analysis. The alloy exhibited superior hydrogen absorption and desorption behavior with 3.2 wt% absorption within 1 min at 573 K and about 3 wt% desorption within 5–10 min at 573 K. This favorable behavior of Mg–Ni compound for the hydrogen storage is due to the specific nanostructure of the material. The low activation energy values and favorable thermodynamics indicate that the prepared Mg–Ni alloy is an attracting material for hydrogen storage applications.
基金financially supported by the National Key Research and Development Program of China (Nos.2023YFB3710401 and 2023YFB3710403)the State KeyLaboratory for Advanced Metals and Materials.
文摘This study investigates the effect of Ce content on the hydrogen storage properties of Ti_(0.98)Zr_(0.02)Mn_(1.5)Cr_(0.05)V_(0.43)Fe_(0.09)Ce_(x)(x=0,0.02,0.04,and 0.06,at%)alloys.Microstructural analysis of these alloys revealed dendritic microstructures without the segregation of chemical elements,with the C14 Laves phase identified as the dominant phase.After two activation cycles at 4 MPa and 293 K,the alloys exhibited excellent hydrogen absorption properties.The addition of Ce significantly improved the kinetics of the alloys.At x=0.02,the hydrogen absorption capacity reached 90%of its maximum within 137 s at 293 K.Pressure-composition-temperature curves indicated that hydrogen absorption capacity initially increased first and then decreased with increasing Ce content,reaching a maximum value of 1.85wt%at x=0.04.Thermodynamic results demonstrated that the enthalpy and entropy of hydrogen absorption followed a similar trend,which was consistent with the variation in hydrogen storage capacity.Thus,the improvement in hydrogen absorption capacity due to the addition of Ce is attributed to the increase in enthalpy.The increase of the lattice constant in the C14 Laves phase and the deoxidization effect of Ce are expected to be beneficial for the improvement of hydrogen absorption kinetics.
