Size-Dependent Kinetic Enhancement in Hydrogen Absorption and Desorption of the Li-Mg-N-H System
Size-Dependent Kinetic Enhancement in Hydrogen Absorption and Desorption of the Li-Mg-N-H System
复制标题
Li-Mg-N-H 体系氢吸收和解吸的尺寸依赖性动力学增强
DOI：
10.1021/ja806565t
复制
发表时间：
2009-02-11
影响因子：
15
通讯作者：
Wang, Qidong
中科院分区：
文献类型：
--
作者：
Liu, Yongfeng;Zhong, Kai;Wang, Qidong
高的工作温度和缓慢的动力学阻碍了Li-Mg-N-H体系储氢的实际应用。为了缓解这些问题，首次尝试通过烧结Mg(NH2)(2)-2LiNH(2)的混合物来合成Li2MgN2H2，并研究了其尺寸依赖的储氢性能。随着颗粒尺寸的减小，吸放氢动力学得到显著提高。通过等温氢脱附曲线的线性作图分析，首次确定了脱氢反应为三维扩散控制的动力学机理。对Li-Mg-N-H体系脱氢动力学的实验改进和机理认识，为进一步降低酰胺/氢化物组合材料的操作温度和提高吸放氢速率提供了理论依据。
High operating temperature and slow kinetics retard the practical applications of the Li-Mg-N-H system for hydrogen storage. To alleviate these problems, a first attempt was carried out by synthesizing Li2MgN2H2 through sintering a mixture of Mg(NH2)(2)-2LiNH(2) and investigating its size-dependent hydrogen storage performance. A dramatically enhanced kinetics for hydrogen absorption/desorption was achieved with a reduction in the particle size. For the dehydrogenation reaction, a three-dimensional diffusion-controlled kinetic mechanism was identified for the first time by analyzing isothermal hydrogen desorption curves with a linear plot method. The experimental improvement and mechanistic understanding on the dehydrogenation kinetics of the Li-Mg-N-H system shed light on how to further decrease the operating temperature and enhance the hydrogen absorption/desorption rate of the amide/hydride combined materials.