Energy Harvesting From CO2 Emissions: The Role of Gas Concentration, Flow, and Supporting Electrolyte

This work explores an innovative approach to convert CO2 into a valuable energy resource using ionic liquid (IL)–based electrochemical systems. The employed ionic liquid, [DBUH][Im], combines the strong CO2 affinity of imidazole with the high basicity of DBU, promoting selective carbamate formation while suppressing parasitic reactions. CO2 chemisorption induces ion rearrangement at the electrode–electrolyte interface, generating a measurable open-circuit voltage shift. However, the high viscosity of the pristine IL significantly restricts ionic mobility, especially after CO2 absorption. Dilution with propylene carbonate improves conductivity and enhances electrochemical performance. A multiparametric study was conducted under realistic working conditions, evaluating gas flow rate influence, CO2/N2 selectivity, operating temperature, and long-term stability. Moreover, the introduction of a supporting-salt further improved ionic conductivity, interfacial properties, and pore accessibility, leading to higher capacitance and harvested power. Overall, these results highlight the potential of tailored IL-based electrolytes for integrated CO2 capture and energy conversion technologies.