Engineering Carbon-Based Porous Materials from Selected Precursors for High-Capacity CO2 Capture

The mitigation of climate change is one of the major global challenges in the 21st Century. Carbon capture and storage (CCS) is a promising technology to effectively reduce anthropogenic CO2 emissions into the Earth’s atmosphere. There are various candidate materials for CO2 capture but each has its own advatanges and disadvantages. Carbon-based materials are of low-cost and have relatively high cyclicity for CO2 and its porous structure and surface functional groups can be tailored to improve CO2 capture performance. Effective but low-cost carbon precursors need to be explored for potential mass production in the furture. This research aims to explore various polymeric, biomass and graphitic materials as the precursors for the development of effecive carbon sobents for CO2 capture. In addition, the influence of porous structures and chemical dopants on CO2 sorption are also experimentally studied in relation to the porosities and surface chemistry of the sorbents. Five distinct synthesis approaches are explored comparatively to determine the potential of polymeric, biomass and graphitic materials as precursors for effective carbon sorbents. These approaches include a novel method of producing millimetre-sized carbon spheres from poly(acrylonitrile-co-acrylamide)/DMSO solution, chemical activation of London Plane leaves, spruce pine cones and graphite oxide, and ball-milling of graphite. The work on the polymer-derived carbon spheres produced desirable carbon macro-spheres with radially channelled and hierarchically porous structures, via a “one-pot” solvent exchange process. The structure shows excellent CO2 capacity of 16.7 wt% at 25 °C and under 1 bar CO2, enhanced by rich nitrogen doping and microporosities. The biomass-derived carbon sorbents further clarify the influence of metal-dopants, inherited from the biomass precursors, on CO2 adsorption. It was noted that besides nitrogen dopant and ultramicropores (