Phase evolution,hydrogen storage thermodynamics and kinetics of ternary Mg_(90)Ce_5Sm_5 alloy |
| |
| Affiliation: | 1. Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081, China;2. Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010, China;1. Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081, China;2. Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010, China;1. Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081, China;2. Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010, China;1. Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010, China;2. Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081, China;3. Weishan Cisri-Eare Earth Materials Co., Ltd., Jining 277600, China;4. Department of Mechanical Engineering, Hebei University, Baoding 071002, China;1. Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081, China;2. Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010, China;3. Beijing Key Laboratory of Precision Alloys, Beijing 100081, China;1. Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing, 100081, China;2. Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou, 014010, China;3. Research Institute for Energy Equipment Materials, Hebei University of Technology, Tianjin, 300130, China |
| |
| Abstract: | Greatly stable thermodynamics and sluggish kinetics impede the practical application of Mg-based hydrogen storage alloys.The modifications of composition and structure are important strategies in turning these hydrogen storage properties.In this study,Mg-based Mg_(90)Ce_5 Sm_5 ternary alloy fabricated by vacuum induction melting was investigated to explore the performance and the reaction mechanism as hydrogen storage material by X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscopy(TEM) and pressure-composition isotherms(PCI) measurements.The results indicate that the Mg-based Mg_(90)Ce_5 Sm_5 ternary alloy consists of two solid solution phases,including the major phases(Ce,Sm)5 Mg_(41) and the minor phases(Ce,Sm)Mg_(12).After hydrogen absorption,these phases transform into the MgH2 and(Ce,Sm)H_(2.73) phase,while after hydrogen desorption,the MgH2 transforms into the Mg phase,but the(Ce,Sm)H2.73 phases are not changed.The alloy has a reversible hydrogen capacity of about 5.5 wt% H_2 and exhibits well isothermal hydrogen absorption kinetics.Activation energy of 106 kJ/mol was obtained from the hydrogen desorption data between 573 and 633 K,which also exhibits the enhanced kinetics compared with the pure MgH2 sample,as a result of bimetallic synergy catalysis function of(Ce,Sm)H_(2.73) phases.The rate of hydrogen desorption is controlled by the release and recombination of H_2 from the Mg surface.Furthermore,the changes of enthalpy and entropy of hydrogen absorption/desorption were calculated to be-80.0 kJ/mol H_2,-137.5 J/K/mol H_2 and 81.2 kJ/mol H_2,139.2 J/K/mol H_2,respectively. |
| |
| Keywords: | Hydrogen storage Reaction mechanism Kinetics Thermodynamics Activation energy Rare earths |
| 本文献已被 CNKI ScienceDirect 等数据库收录！ |
|
