Three-Dimensional Graphene-Based Porous Adsorbents for Postcombustion CO2 Capture

Three-dimensional (3D) crumpled graphene-based porous adsorbents with highly interconnected networks were synthesized through a facile one-step physical activation method using reduced graphene oxide (RGO) as precursor, for separation of carbon dioxide (CO 2 ) from postcombustion flue gas mixtures. Due to their large surface area (above 1300 m 2 g –1 ), high pore volume (over 1 cm 3 g –1 ), and well-defined bimodal microporous–mesoporous structure, these hierarchical porous graphene-based materials demonstrate rapid, stable, reversible, and high CO 2 uptake of 2.45 mmol g –1 at 25 °C and 1 bar. Importantly, the CO 2 over nitrogen (N 2 ) adsorption selectivity is among the best at partial pressures relevant to capturing CO 2 emanating from postcombustion power plants fueled with either coal or natural gas. Moreover, the isosteric heat of adsorption of only −27.42 kJ mol –1 at zero coverage reflects the ease of adsorbent regeneration with significantly low energy consumption, which in turn might reduce the costs of carbon capture and sequestration.