Synthesis of three coordination polymer microspheres and their application in hydrogen storage

In this paper, three coordination polymer microspheres based on different metal ions have been fabricated via solvothermal method by using 1,1′-ferrocenedicarboxylic acid as organic linker. The as-synthesized samples are of high local crystalline ordering, as confirmed by powder X-ray diffraction patterns. These materials cannot only remain stable up to nearly 400°C, but also have improved hydrogen storage capacity, reaching 1.60 wt%, 2.12 wt% and 1.22 wt% at 163 K, 5 MPa. The influence of metal ions on hydrogen uptake capacity has investigated and the corresponding adsorption enthalpy has been calculated. The comparison between these three microspheres indicates that the impact of metal ions follows the trend of Zn²⁺ < Mn ²⁺ < Co²⁺, which is a useful conclusion for future material design.