A carbonaceous particulate material is provided that is characterized by having a reversible volumetric expansion/contraction in fluid media (“VR”) of greater than or equal to (≧)3% between 4,000 psi and 10,000 psi. The porous carbonaceous particulate material of the present disclosure is also characterized by having a true density, (“PT”), of 1.2 g/cc≦PT≦2.0 g/cc, when milled to−-200 mesh and has a d50 particle size distribution of about 15 μm. This is the consequence of the instant material exhibiting a high level of closed porosity with very small pores, in contrast with prior art materials that would have a wider range pore sizes for the closed pores.