Bhati, Geetanjali2025-04-072025-04-072025ROLL NO.166107117https://gyan.iitg.ac.in/handle/123456789/2869Supervisors: Mandal, Bishnupada and Uppaluri, RamagopalThis Ph.D. research works addressed enhanced CO₂ capture through the adsorption-based processes and with Zeolite-Y as the primary support material. To assess alternate commercial as well as synthesized sorbents, single gas sorption experiments with CO2, N2 and CH4 were conducted. Among alternate sorbents, Zeolite-Y was selected after comparing its CO₂ adsorption capacity (highest of 1.89 mmol g-1 at 303K and 1bar) with respect to other commercial zeolites (Beta and ZSM-5 commercial sorbents). After selecting Zeolite Y as the primary support material, the study followed a three-phase approach. Among these, firstly, Zeolite-Y was functionalized with mono-, di-, and triethanolamine. Thereby, the monoethanolamine-loaded samples exhibited the highest CO₂ uptake (up to 2.26 mmol/g at 303 K and 1 bar). The adsorption behavior was modeled with the Langmuir and Virial isotherm, and selectivity was assessed via IAST. In the second phase, cation-loaded Zeolite-Y (Li⁺, Na⁺, K⁺ at 5 wt.%) were prepared and the sorbents exhibited enhanced CO₂ selectivity and for the loading order of K⁺ > Na⁺ > Li⁺. Among all, potassium loaded Zeolite Y sorbent exhibited highest CO2 uptake (2.89 mmol g-1 at 303K and 1bar). The third phase examined K₂CO₃-impregnated Zeolite-Y. Accordingly, the variant carbonate loadings affirmed optimal CO₂ capacity at 10 wt.% loading of the carbonate (3.61 mmol g-1 at 303K and 1bar). Also, the synthesized functional materials exhibited excellent cyclic stability and selectivity. In summary, the Ph.D. thesis research works novelty can be mentioned in terms of cation-carbonate loading for cost-effective, stable and high-performance zeolite-based adsorbents and for the proximity towards industrial-scale CO₂ capture.enThesis