Theoretical calculations of a porous coordination polymer formed by isonicotinylhydrazine, 1,4-benzenedicarboxylic and Co2+: electronic properties, lithium doping, and H2 adsorption studies

The present work is focused in the theoretical study of a porous coordination polymer formed by isonicotinylhydrazine (INH), 1,4-benzenedicarboxylic (14BDC) acid, and Co2+. This coordination polymer [Co{CP}] was studied by density of states and charge density difference, which allowed determining its electronic properties, transitions of valence to conduction band and its post-synthesis capacity. We have also evaluated the possibility of inserting lithium into the structure and observed that the resulting structure is stable and energetically favorable. Furthermore, taking into account gas adsorption applications, the insertion of a H2 was also conducted in both [Co{CP}] and lithium-doped structure. Our results have showed that the adsorption of hydrogen in Co{CP} is energetically unfavorable, while in the lithium-doped structure, it showed remarkable potential. Overall, we were able to show in this work after thorough calculation that the insertion of lithium ions into the coordination polymer structure is highly beneficial, improving drastically its hydrogen adsorption ability, which opens a wide window of opportunities towards the development of new coordination polymers for gas adsorption.