Bullet-like vanadium-based MOFs as a highly active catalyst for promoting the hydrogen storage property in MgH_(2)  

作　　者：Zhiyu Lu Jiahuan He Mengchen Song Yan Zhang Fuying Wu Jiaguang Zheng Liuting Zhang Lixin Chen 

机构地区：[1]School of Energy and Power,Jiangsu University of Science and Technology,Zhenjiang 212003,China [2]Instrumental Analysis Center,Jiangsu University of Science and Technology,Zhenjiang 212003,China [3]State Key Laboratory of Silicon Materials,Department of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2023年第1期44-53,共10页矿物冶金与材料学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No. 51801078);the Natural Science Foundation of Jiangsu Province (No. BK20180986)

摘　　要：The practical application of magnesium hydride(MgH_(2))was seriously limited by its high desorption temperature and slow desorp-tion kinetics.In this study,a bullet-like catalyst based on vanadium related MOFs(MOFs-V)was successfully synthesized and doped with MgH_(2) by ball milling to improve its hydrogen storage performance.Microstructure analysis demonstrated that the as-synthesized MOFs was consisted of V_(2)O_(3) with a bullet-like structure.After adding 7wt%MOFs-V,the initial desorption temperature of MgH_(2) was reduced from 340.0 to 190.6℃.Besides,the MgH_(2)+7wt%MOFs-V composite released 6.4wt%H_(2) within 5 min at 300℃.Hydrogen uptake was started at 60℃under 3200 kPa hydrogen pressure for the 7wt%MOFs-V containing sample.The desorption and absorption apparent activity energies of the MgH_(2)+7wt%MOFs-V composite were calculated to be(98.4±2.9)and(30.3±2.1)kJ·mol^(-1),much lower than(157.5±3.3)and(78.2±3.4)kJ·mol^(−1) for the as-prepared MgH_(2).The MgH_(2)+7wt%MOFs-V composite exhibited superior cyclic property.During the 20 cycles isothermal dehydrogenation and hydrogenation experiments,the hydrogen storage capacity stayed almost unchanged.X-ray diffraction(XRD)and X-ray photoelectron spectrometer(XPS)measurements confirmed the presence of metallic vanadium in the MgH_(2)+7wt%MOFs-V composite,which served as catalytic unit to markedly improve the hydrogen storage properties of Mg/MgH_(2) system.

关 键 词：hydrogen storage magnesium hydrides vanadium based MOFs catalytic mechanism 

分 类 号：TQ426[化学工程]