Hierarchically Porous Carbon Materials for CO 2 Capture: The Role of Pore Structure

With advances in porous carbon synthesis techniques, hierarchically porous carbon (HPC) materials are being utilized as relatively new sorbents for CO 2 capture applications. These HPC materials were used as a platform to prepare samples with differing textural properties and morphologies to elucidate structure–property relationships. It was found that high microporous content, rather than overall surface area, was of primary importance for predicting good CO 2 capture performance. Two HPC materials were analyzed, each with near identical high surface area (∼2700 m 2 /g) and colossally high pore volume (∼10 cm 3 /g), but with different microporous content and pore size distributions, which led to dramatically different CO 2 capture performance. Overall, large pore volumes obtained from distinct mesopores were found to significantly impact adsorption performance. From these results, an optimized HPC material was synthesized that achieved a high CO 2 capacity of ∼3.7 mmol/g at 25 °C and 1 bar.