Surface modification of MgH2 by ZrCl4 to tailor the reversible hydrogen storage performance
Surface modification of MgH2 by ZrCl4 to tailor the reversible hydrogen storage performance
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DOI：
10.1016/j.ijhydene.2017.01.193
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发表时间：
2017-03
影响因子：
7.2
通讯作者：
Sanjay Kumar;A. Jain;Shotaro Yamaguchi;H. Miyaoka;T. Ichikawa;A. Mukherjee;G. K. Dey;Y. Kojima
中科院分区：
文献类型：
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作者：
Sanjay Kumar;A. Jain;Shotaro Yamaguchi;H. Miyaoka;T. Ichikawa;A. Mukherjee;G. K. Dey;Y. Kojima
四氯化锆（ZrCl_4）是改善MgH_2-Mg体系可逆储氢性能的最佳催化剂之一。MgH 2在ZrCl 4催化下的表观活化能显著降低，脱氢和再氢化动力学得到改善。X射线光电子能谱（XPS）分析表明，MgH 2球磨后ZrCl 4以ZrCl 3和金属Zr的形式存在。原位生成的ZrCl 3和金属Zr对MgH 2有很好的催化作用，可显著降低脱氢和再氢化温度。扫描电子显微结构分析表明，该催化剂具有良好的晶粒细化性能，在球磨过程中降低了MgH 2的晶粒尺寸。微晶尺寸的减小减小了氢的扩散路径长度，并增加了MgH 2-Mg的活性表面积，这最终增强了脱氢和再氢化动力学。
Zirconium tetrachloride (ZrCl4) is one of the best catalysts for improving the reversible hydrogen storage performance of the MgH2–Mg system. MgH2catalyzed by ZrCl4shows a remarkably reduced apparent activation energy, which leads to improved dehydrogenation and rehydrogenation kinetics. X-ray photoelectron spectroscopy (XPS) revealed the chemical state of ZrCl4as ZrCl3and metallic Zr after ball milling with MgH2. Thein situ-formed ZrCl3and metallic Zr showed good catalytic effect on MgH2,which substantially lowered the dehydrogenation and rehydrogenation temperatures. The scanning electron microstructure analysis revealed the excellent grain refinement property of the catalyst to reduce the crystallite size of MgH2during ball-milling. The decreased crystallite size reduces the diffusion path length of hydrogen and increases the active surface area of MgH2–Mg, which eventually enhances the dehydrogenation and rehydrogenation kinetics.