Hydrogen physisorption in different carbonaceous materials was investigated in liquid nitrogen (77 K). The total hydrogen adsorption was found to have a linear relationship with the surface area of pores <30 A. The surface area and porosity of the carbon materials were determined by dinitrogen adsorption at 77 K and density function theory (DFT). The active sites for hydrogen adsorption were investigated and found to be related to the edge orientation of defective graphene micro-sheet domains.