Why is this research needed?
CCS heavily relies on a range of materials and technologies developed to prevent CO2 emissions to the atmosphere. Among these materials, metal-organic frameworks (MOFs) have been widely explored for their potential in CO2 capture. MOFs gained popularity in CCS due to their large surface areas and adjustable pore sizes and good thermal stability, resulting in good selectivity and capacity for adsorbing gases like CO2. However, one major issue MOFs face is the structural instability, which is susceptible to ligand substitution by water and other nucleophiles, leading to collapsed network upon exposure to moist air. Also, the non-covalent nature of MOF structures impedes their incorporation with other carbon capture and more importantly utilisation materials and technology. In addition, the high cost of commercialised MOFs limits the practical applications of the materials, with retail prices ranging from US$10 to 15 per gram.
What is this research investigating?
CB, a new type of polymer, has an uptake capacity of 26 mL g-1 for CO2, comparable to MOFs, while much higher than that of the uptake capacity for N2, O2 and CO, thus highly selective for CO2 adsorption. Moreover, the carbonyl groups at the portal of CB allow the formation of complexes with cations such as Co2+, Ni2+, Cu2+, Pb2+, Zn2+,Cd2+, Cr2+ and Fe2+, leading to potential catalytic sites for captured CO2 to be in-situ converted to valuable chemicals. In addition, CB are stable in the presence of water. The project aims not only to synthesise a CB-incorporated membrane for CCS but also to embed photocatalysts (eg. Cu2O, C3N4) into the CB-incorporated membranes for carbon capture and utilisation (CCU). Thus a photocatalytic membrane reactor will be generated and investigated in the project for CO2 conversion to high value chemicals.
What does the research hope to achieve?
This project’s target is to produce a new type of CO2 adsorbent membrane CB and more importantly to convert the waste CO2 to valuable chemicals/fuels by a photocatalytic membrane reactor.