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oai:figshare.com:article/32826014 2026-10-01T16:11:32Z portal_1172 item_type_8 month_year_10_2026

Integrated CO2 capture and utilisation: exploring dual-functional materials and molten salt media Xiaotong Zhao (741280) PUREID: 638653398 CO2 capture and conversion molten salts solar energy carbon dioxide Global warming drives the need for intergrated carbon capture and utilisation (ICCU) technologies. This study investigates dual-functional materials (DFMs) for ICCU-dry reforming of methane (ICCU-DRM) and ICCU-reverse water-gas shift (ICCU-RWGS) reactions. <br><br>A Ni0.05/CaO0.95 DFM was evaluated under various simulated flue gas conditions (10 % CO2/N2; 10 % CO2 + 6% H2O/N2; 10 % CO2 + 6.7 % O2/N2; 10 % CO2 + 6 % H2O + 6.7 % O2/N2) at 650  ℃ and atmospheric pressure. Each cycle involved 30 min CO2 capture, 5 min N2 purge, and CH4 conversion with 10 % CH4/N2. Characterizations (XRD, in-situ DRIFTS, CH4-TPR, SEM, EDX, FIB-SEM, BET, XPS) revealed that O2 and H2O severely degraded performance by oxidizing Ni and causing CaO/Ni volumetric expansion, forming dense shells that hindered NiO reduction.<br><br>Decoupled experiments using Ni/SiO2 catalysts and sol-gel CaO sorbents demonstrated that Ni activated adsorbed CO2 to react with coke from CH₄ decomposition, with catalyst-sorbent contact critical for the reverse Boudouard reaction. DFT calculations and in-situ DRIFTS confirmed CO2 chemisorption on Ni surfaces.<br><br>For ICCU-RWGS, a CaO–NaCl–CaCl2 molten salt system (NaCl:CaCl2 = 4:6) operated between 600 to 750  ℃ improved CO2 uptake and conversion efficiency by enhancing CaO dispersion and carbonate solubility. Additionally, a molten Li2CO3–Na2CO3–K2CO3 (1:1:1) and boric acid system at 650  ℃ achieved stable CO2 uptakes (2.0, 1.1, 1.3 mmol per cycle for Li, Na, and K carbonates) and 51 to 58 % conversion over 10 cycles.<br><br>This work reveals how flue gas components impact DFM stability, emphasizes catalyst-sorbent interactions, and demonstrates that molten salt environments significantly enhance ICCU-RWGS efficiency, supporting the integration of renewable energy sources like concentrated solar power. 2026-10-01T16:11:32Z Text Thesis 10.17034/32826014.v1 https://figshare.com/articles/thesis/Integrated_CO2_capture_and_utilisation_exploring_dual-functional_materials_and_molten_salt_media/32826014 All Rights Reserved