Hydrogenated graphene: Important material properties regarding its application for hydrogen storage

Abstract Chemically hydrogenated graphene possesses a theoretical hydrogen storage capacity of 7.7 wt%, and will release H2 gas upon thermal decomposition, making it an intriguing material for hydrogen storage applications. Recent works have demonstrated that this material can be synthesized at multi-gram scale quantities, and it has already been safely demonstrated as a hydrogen source to power a PEM fuel cell. While these results are promising, further characterization and evaluation of this material as it pertains to hydrogen storage must be carried out. In this work, we characterize various properties of chemically hydrogenated graphene, which will be key in the application of this material as a hydrogen storage medium moving forward. These include: theoretical calculation of the material's total volumetric energy density, the dependence of both temperature and surrounding atmosphere on the release of hydrogen gas, thermal expansion of the material upon heating, and the activation energy associated with hydrogen release.