Presentation description

Rising atmospheric concentrations of carbon dioxide (CO₂), driven primarily by fossil fuel combustion, pose a critical challenge due to their role in accelerating global climate change. The increase in atmospheric CO₂ and its threat to the environment underscore the urgent need for sustainable carbon management technologies. Electrochemical CO₂ reduction (CO₂RR) presents a strategy for mitigating CO₂ emissions, but it typically requires large negative potentials, limiting its energy efficiency and scalability. In this study, we investigate oxalate-mediated pathways for CO₂RR as a more energy-efficient method of reduction. In aqueous conditions, oxalate (C₂O₄²⁻) undergoes two-electron oxidation to produce CO₂, while in polar aprotic solvents, oxalate forms a reversible adduct with CO₂ that facilitates reduction at less negative potentials. We explore the impact of oxalate and structurally related compounds - dimethyl oxalate, citrate, pyruvate, and succinate - on CO₂RR in five different polar aprotic solvents: MeCN, DMF, DMA, DMSO, and formamide. In DMF, the reduction of pure CO₂ occurs near -2.8 V (vs. Ag/AgO). Notably, increasing the concentration of oxalate lowers this reduction potential, suggesting that oxalate and similar compounds can effectively facilitate CO₂RR at less negative reduction potentials. This work highlights a pathway toward more efficient CO₂ reduction by leveraging molecular interactions between CO₂ and carboxylate-containing compounds, potentially offering a foundation for future development of electrochemical systems that enable selective, low-energy CO₂ reduction and utilization.