The growing global concern over rising CO2 emissions and its significant impact on climate change highlight the urgent need for efficient CO2 capture technologies. Among the array of techniques employed for this purpose, chemical absorption stands out, characterized by high capture capacity, promising efficiency, and versatile applicability. In this context, Ionic liquids (ILs) and their analogs, deep eutectic solvents (DES), have emerged as promising alternatives to conventional solvents due to their low vapor pressures, high thermal stability, and chemical tunability. However, they also face challenges of high viscosity and cost. Studies have identified two promising strategies to address these limitations: (i) using low-viscous solvents to mix with ILs/DESs and (ii) immobilizing ILs/DESs over a large surface (solid porous materials) to develop composites. The goal of this thesis was to integrate these two strategies to develop an innovative sorbent with enhanced CO2 capture capacity while improving kinetics. The main progress achieved in this thesis is as follows:

In the first part, ILs/DESs were screened from the properties where a literature survey was combined with COSMO-RS for different IL/DES-based technologies. One DES was selected. To study the CO2 capture using immobilized ILs/DESs, porous adsorbents were evaluated based on a literature survey by considering the surface area, pore size/volume, stability, availability, and price. Mesoporous silica was selected as a suitable substrate for immobilization. 

In the second part, a range of aqueous DESs was developed based on the molar ratio of DES components and water content for CO2 capture. Then, the CO2 capture capacity and viscosity of aqueous DESs (before and after absorption) were systematically evaluated and compared with a commercial absorbent. An optimal solution was then selected to achieve a balance between higher CO2 capture capacity and lower viscosity. Additionally, absorption kinetics, recyclability, and the effect of temperature on CO2 capture capacity were studied.

In the third part, studies were directed towards the novel strategy, i.e., developing sorbent via integrating aqueous and immobilized DESs, i.e., slurry. To this end, DES was immobilized into mesoporous silica at different loadings and mixed with the aqueous DES. Their CO2 capture capacity was measured and the optimal slurry, selected based on CO2 capture performance, underwent further analysis to evaluate kinetics, recyclability, and temperature effect on performance and obtained results were compared with a commercial solvent.