Exceptional CO2 capture in a hierarchically porous carbon with simultaneous high surface area and pore volume

Abstract

A new type of hierarchically porous carbon (HPC) structures of simultaneously high surface area and high pore volume has been synthesised from carefully controlled carbonization of in-house optimised metal–organic frameworks (MOFs). Changes in synthesis conditions lead to millimetre-sized MOF-5 crystals in a high yield. Subsequent carbonization of the MOFs yield HPCs with simultaneously high surface area, up to 2734 m² g⁻¹, and exceptionally high total pore volume, up to 5.53 cm³ g⁻¹. In the HPCs, micropores are mostly retained and meso- and macro- pores are generated from defects in the individual crystals, which is made possible by structural inheritance from the MOF precursor. The resulting HPCs show a significant amount of CO₂ adsorption, over 27 mmol g⁻¹ (119 wt%) at 30 bar and 27 °C, which is one of the highest values reported in the literature for porous carbons. The findings are comparatively analysed with the literature. The results show great potential for the development of high capacity carbon-based sorbents for effective pre-combustion CO₂ capture and other gas and energy storage applications.