Jerzy Szpunar

Abstract:

The storage of hydrogen will also require structural modification of the storage system. One of storage systems that was developed by us will be discussed. We designed a Pd-graphene composite for hydrogen storage with spherical shaped nanoparticles of 45 nm size, homogeneously distributed over a graphene substrate. This new hydrogen storage system has attractive features like high gravimetric density, ambient conditions of hydrogen charge and low temperature of the hydrogen discharge. The palladium particles produce a low activation energy barrier to dissociate hydrogen molecules These Pd particles, have to be nano-size and homogeneously dispersed on the graphene surface, to serve as efficient hydrogen receptors and further facilitate a dissociation and diffusion of hydrogen and storage in graphene via a spillover process. The hydrogen storage capacity in such a combined metal-graphene system could be significantly increased compared to storage in graphene or in metal. In this project, we optimized the structure of Pd/graphene to allow a hydrogen uptake at ambient conditions and discharging of hydrogen at low temperature. In particular, with hydrogen charging pressure of 60 bar, the Pd/graphene composite system with a Pd loading amount of 1 at. % captures 10 wt. % of hydrogen.