Three-Dimensional Graphene-Based Porous Adsorbents for Postcombustion CO2 Capture
journal contributionposted on 19.02.2016, 00:00 by Shamik Chowdhury, Rajasekhar Balasubramanian
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 (CO2) from postcombustion flue gas mixtures. Due to their large surface area (above 1300 m2 g–1), high pore volume (over 1 cm3 g–1), and well-defined bimodal microporous–mesoporous structure, these hierarchical porous graphene-based materials demonstrate rapid, stable, reversible, and high CO2 uptake of 2.45 mmol g–1 at 25 °C and 1 bar. Importantly, the CO2 over nitrogen (N2) adsorption selectivity is among the best at partial pressures relevant to capturing CO2 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.