Abstract
Mg-Li alloy is a lightweight hydrogen storage material with high hydrogen capacity,but its poor kinetics limited its practical applications.In this work,MCM-22 molecular sieve was added to Mg-Li alloy by friction stir processing(FSP)as the catalyst to enhance the kinetic properties of Mg-Li alloy(denoted as Mg-Li-MCM-22).The resulting Mg-Li-MCM-22 possesses the reversible hydrogen storage capacity of ca.6 wt.%and can release 5.62 wt.%hydrogen within 50 min at 623 K,showing improved kinetics.The Chou model and Johnson-Mehl-Avrami-Kolmogorov(JMAK)model calculations reveal that the lattice defects generated by FSP improve the kinetics of hydrogen adsorption/desorption.The pinning effect of MCM-22 particles produces more grain boundaries and dislocations,thus,increasing the diffusion rate of hydrogen atoms and providing more nucleation sites,therefore,reducing the dehydrogenation activation energy.This work provides a new strategy for the preparation of hydrogen storage materials.
基金项目
中央高校基本科研业务费专项(2022CDJKYJH028)
国家自然科学基金(52271091)
Chongqing Special Key Project of Technology Innovation and Application Development,China(cstc2019jscxdxwtBX0016)