Size-Dependent Kinetic Enhancement in Hydrogen Absorption and Desorption of the Li-Mg-N-H System

作者：Liu, Yongfeng; Zhong, Kai; Luo, Kun; Gao, Mingxia; Pan, Hongge^*; Wang, Qidong

来源：Journal of the American Chemical Society, 2009, 131(5): 1862-1870.

DOI：10.1021/ja806565t

• SOLID-STATE REACTION
• STORAGE PROPERTIES
• MECHANISM
• AMIDE
• DECOMPOSITION
• MG(NH2)(2)
• LINH2-MGH2
• LI2NH

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.

• 出版日期2009-2-11
• 单位浙江大学