High-Throughput Computational Screening of Quinones for Electrochemical CO2 Capture

Electrochemical carbon capture (ECC) with quinones is a promising, energy-efficient alternative to thermal systems, but oxygen sensitivity remains a significant challenge. The persistent trade-off between CO2 affinity (KCO2) and reduction potentials (Ered) requires identifying "borderline" species amenable to system-level optimization. Using density functional theory (DFT), we screened 31,000 quinones and identified 681 candidates with parameters suitable for oxygen-tolerant ECC. Our screening revealed unexplored structural motifs, including heterocyclic and extended aromatic systems, alongside intramolecular H-bonding effects. We also identified functional groups prone to structural fragmentation upon CO2 binding, which are unsuitable for durable operation despite favorable potentials. Finally, synthetic feasibility was assessed via a dual-metric approach, narrowing the selection to 20 high-priority quinones for experimental validation. This study provides a rational design roadmap for high-performance organic ECC sorbents.