Porous Graphene Oxide Framworks And Composites For CO₂ Capture And Separation

CO2 is the main greenhouse gas, the optimization and design of high-performance materials for carbon capture and separation is the major challenge facing society today. Porous metal-organic frameworks (MOFs) as carbon capture new materials show obvious advantages in structural design and performance regulation, but still exist some insignificances, such as the renewable energy and adsorption capacity are difficult to balance and relatively low thermal stability. We obtained high adsorption capacity and low regeneration energy material UTSA-16 by utilizing the synergistic effect between subject and object with the weak force, but still unable to determine the optimal spacing among groups to provide weak force synergistic effect. In this paper, graphene oxide (GO) is regarded as the main object of study. For the optimization spacing problem, we selected porous graphene oxide frameworks (GOFs) synthesized from GO and organic boronic acid as a model, to obtain high adsorption capacity and low regeneration energy optimization GOF materials with optimized GO layer spacing for 10.3 A by varying the reactants and reaction conditions to regulate some parameters such as GOFs spacing, the specific surface area, CO2 adsorption amount and adsorption enthalpy. This work provides a basis and guidance for desiging high performance CO2 capture material. For the thermal stability problem, we selected GO and lower thermal stability UTSA-16 to synthesis the first case of core-shell type MOF-GO composite. Armored with GO film make the thermal stability enhance from mather material for 139℃ to composite for 280 ℃, and the CO2/CH4 selectivity increase from 29.8 to 114.4 ranking second place in the reported cases so far. Further, we selected GO and MIL-101(Cr) to obtain composites. After obtaining composite, the BET surface area of the material increased by 50%, the CO2 and C2H2 adsorption capacities at ambient temperature and pressure increased from 45.5 and 65.6 cm3/g to 57.7 and 85.1 cm3/g, and the results of breakthrough experiment showed have good separation effect of CO2/N2 under dry and humit condition. The method by selecting GO and MOFs to obtain composite provides a new way of thinking for improving the usefulness and enhancing the overall performance of MOFs material.