Integrating CO₂ capture with electrochemical conversion offers a promising pathway to reduce the energy penalty associated with conventional solvent regeneration. In this context, the development of suitable solvents is crucial. In this study, we develop a non-aqueous Monoethanolamine (MEA)-based solvent composed of Choline Chloride (ChCl) and Ethylene Glycol (EG), designed to function simultaneously as a CO₂ absorbent and an electrolyte in an electrolyzer, thereby eliminating the need for intermediate solvent regeneration steps. Vapor-liquid equilibrium (VLE) measurements were performed to quantify chemical CO₂ absorption, while N₂O was used as an analogue gas to assess the physical CO₂ absorption. Although conventional 30 wt.% aqueous MEA exhibited stronger CO₂ binding at low CO₂ partial pressures (≤1 kPa), our non-aqueous MEA solvent demonstrated markedly higher capacities at moderate to high CO₂ partial pressures (up to 500 kPa), reaching up to 1.2, 1.1, and 0.9 mol CO₂/mol MEA at 25, 40, and 65 °C, respectively, exceeding the theoretical equilibrium limit of aqueous MEA. FTIR spectroscopy identified a transition from predominant carbamate formation at low CO₂ partial pressures to increased carbonate formation derived from EG, together with enhanced physical dissolution at higher CO₂ concentrations, indicating distinct and pressure-dependent reaction pathways. Evaluation of key physical properties, including viscosity, electrical conductivity, and thermogravimetric analysis (TGA), highlighted the critical role of solvent formulation in enabling process integration. While incorporation of ChCl increased viscosity due to its ionic nature, it substantially enhanced thermal stability and provided intrinsic ionic conductivity required for electrochemical operation. Overall, this work demonstrates how solvent composition design in non-aqueous solvent systems enables high CO₂ capacity, tunable reaction chemistry, and electrochemical compatibility, offering a practical pathway toward integrated, energy-efficient carbon capture and utilization technologies.

In this study, the effect of halide anions on the selectivity of the CO₂ reduction reaction to CO was investigated in choline-based ethylene glycol solutions containing different halides (ChCl : EG, ChBr : EG, ChI : EG). The CO₂RR was studied using silver (Ag) and gold (Au) electrodes in a compact H-cell. Our findings reveal that chloride effectively suppresses the hydrogen evolution reaction and enhances the selectivity of carbon monoxide production on both Ag and Au electrodes, with relatively high selectivity values of 84 % and 62 %, respectively. Additionally, the effect of varying ethylene glycol content in the choline chloride-containing electrolyte (ChCl : EG 1 : X, X=2, 3, 4) was investigated to improve the current density during CO₂RR on the Ag electrode. We observed that a mole ratio of 1 : 4 exhibited the highest current density with a comparable faradaic efficiency toward CO. Notably, an evident surface reconstruction process took place on the Ag surface in the presence of Cl⁻ ions, whereas on Au, this phenomenon was less pronounced. Overall, this study provides new insights into anion-induced surface restructuring of Ag and Au electrodes during CO₂RR, and its consequences on the reduction performance on such surfaces in non-aqueous electrolytes.