Résumé
Hydrogen adsorption in slit shaped pores built up from truncated graphene fragments has been simulated using Grand Canonical Monte Carlo technique and the influence of pore wall edges on hydrogen storage by physisorption has been analyzed. We show that due to the additional gas adsorption at the pore edges the adsorbed gravimetric amount significantly increases (by a factor of two) with respect to models of pores with infinite graphene walls. The contribution of the edges' adsorption to the total hydrogen uptake is independent of the pore wall shape but it depends on its surface. We also show that the maximum of the excess adsorption shifts towards higher pressures when the edge contribution increases. This information can be used to characterize experimentally structures of porous adsorbents and complement pore size distribution analysis usually performed with gases others than hydrogen. We suggest that porous carbons built from polycyclic hydrocarbons can achieve storage performances required for practical applications