Doping of alkali metals in carbon frameworks for enhancing CO2 capture: A theoretical study

We use a multi-scale simulation method that combines the grand canonical Monte Carlo (GCMC) simulations and density function theory (DFT), a series of alkali metals doping in carbon surfaces, and the influence of alkali metal-doped PCs on CO2 uptake were comprehensive study. The results show that all alkali metals can significantly increase the CO2 uptake in carbon surfaces. The enhancement of CO2 adsorption mainly originates from the effects of the large electrostatic interaction and the strong adsorption energy. By the comparative studies above, it is found that the doping of alkali metals into carbon surface for CO2 capture reach 8.43–12.46 mmol g−1, which is about 2.6–3.8 times those in the nondoped one. In combination with its superior selectivity for CO2/N2 and CO2/CH4 at 25 °C, the doping of alkali metals on carbon surface has been shown to be one of the promising adsorbents for CO2 uptake and separation, and provides an effective and excellent alternative strategy for the design and screening of CO2 adsorbents.