Ultrasmall MgH2 Nanoparticles Embedded in an Ordered Microporous Carbon Exhibiting Rapid Hydrogen Sorption Kinetics
Ultrasmall MgH2 Nanoparticles Embedded in an Ordered Microporous Carbon Exhibiting Rapid Hydrogen Sorption Kinetics
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DOI：
10.1021/acs.jpcc.5b05754
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发表时间：
2015-07
影响因子：
3.7
通讯作者：
C. Zlotea;Y. Oumellal;Son-Jong Hwang;C. Ghimbeu;P. Jongh;M. Latroche
中科院分区：
文献类型：
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作者：
C. Zlotea;Y. Oumellal;Son-Jong Hwang;C. Ghimbeu;P. Jongh;M. Latroche
通过调整Mg的量从15到50wt%，制备了具有不同平均尺寸的MgH 2纳米颗粒作为有序的微孔碳。平均尺寸为1.3和3.0 nm的超小颗粒已获得15和25重量%的镁含量，分别。不同的热分析技术证明，氢解吸性能强烈依赖于纳米颗粒的尺寸。对于低于3 nm的MgH 2纳米颗粒，氢解吸的起始温度发生在比微晶材料低约245 K的温度下。两个不同的氢解吸峰注意到平均尺寸为1.3和3.0 nm的纳米粒子，证实了TDS和HP-DSC。1H NMR研究表明，存在两个MgH 2人口与增强的氢流动性，相比，微晶氢化物。短的氢扩散路径和增强的氢迁移率可以解释这些超小纳米颗粒的解吸动力学增加。
MgH2 nanoparticles with different average sizes have been prepared as ordered microporous carbon by tuning the Mg amount from 15 to 50 wt %. Ultrasmall particles with mean sizes of 1.3 and 3.0 nm have been obtained for 15 and 25 wt % Mg contents, respectively. The hydrogen desorption properties strongly depend on the nanoparticle size, as evidenced by different thermal analysis techniques. The onset temperature of hydrogen desorption for MgH2 nanoparticles below 3 nm occurs at a temperature about 245 K lower than for microcrystalline material. Two distinct hydrogen desorption peaks are noticed for nanoparticles with mean sizes of 1.3 and 3.0 nm, as confirmed by TDS and HP-DSC. 1H NMR investigations suggest the presence of two MgH2 populations with enhanced hydrogen mobility, as compared to the microcrystalline hydride. The short hydrogen diffusion path and the enhanced hydrogen mobility may explain the increased desorption kinetics of these ultrasmall nanoparticles.