Electrochemical Routes for Capture and Utilization of CO2

The rapid rise in atmospheric CO2 concentrations presents a critical challenge to global climate stability, necessitating the development of energy-efficient, scalable, and economically viable carbon capture and utilization (CCUS) technologies. This thesis advances integrated electrochemical and materials-based strategies for CO2 capture, activation, and conversion, with particular emphasis on reducing regeneration energy penalties, enhancing reaction kinetics, and enabling operation under dilute CO2 feed conditions relevant to flue gas and air capture. The early chapters of the dissertation establish molecular-level design principles for improving reactive CO2 capture. A fully automated high-throughput screening platform was developed to evaluate ionic conductivity in room-temperature ionic liquids (ILs) and IL–ethylene glycol mixtures, identifying electrolyte formulations that enhance conductivity by up to 200% and reduce the energy consumption of migration-assisted moisture-gradient (MAMG) capture by nearly 50%. Beyond transport enhancement, ILs were shown to play a previously unrecognized catalytic role in accelerating CO2 hydroxylation by locally pre-activating and bending CO2, thereby lowering activation barriers without irreversible binding. Building on these advances, the thesis explores nonaqueous electrochemical CO2 reduction (eCO2R) enabled by microenvironment engineering. By controlling local acidity and electric fields in CO2-soluble electrolytes, selective formation of multi-carbon products was achieved using both lead-based and earth-abundant iron catalysts. These systems demonstrate high selectivity and favorable techno-economic and life-cycle performance, underscoring the importance of electrolyte composition and interfacial design in sustainable CO2 conversion. The latter chapters transition toward fully integrated capture–conversion architectures. A hydroxide-based CO2 capture and release platform combining a hollow-fiber membrane contactor with electrodialysis under a moisture-swing mechanism achieved stable operation at 0.4% CO2 feed with high flux and reduced energy demand. This framework was further extended to a continuous, closed-loop system that directly couples electrochemical CO2 capture with electrochemical reduction to value-added products such as ethylene, CO, and methane through pH-driven rate matching. Ongoing work examines ion transference behavior in IL-based electrolytes to further enhance current efficiency in integrated systems. Collectively, this thesis demonstrates that coupling molecular-level electrolyte design with electrochemical process integration provides a viable pathway for low-energy, continuous CO2 capture and conversion, advancing CCUS technologies toward scalable real-world deployment.

Author dc:creator

• Rohan Sartape (14069294)

• Chemical Engineering
• Chemistry
• Material Science
• Environmental Engineering

Statement dc:rights

• In Copyright

DOI dc:identifier

https://doi.org/10.25417/uic.32991950.v1

OAI identifier oai:identifier

oai:figshare.com:article/32991950