An avenue to break the observed trade-off could be to explore alternative capture agents beyond anthraquinone. Calculations on substituted benzoquinones (BQ) also revealed a trade-off between redox potential and CO 2 capture strength (dashed red line in Figure ), though interestingly we found that both the reduction and carbon capture steps become more thermodynamically favourable relative to AQ, i.e. different trade-off relationships are found for functionalised BQ and AQ molecules. The downsides of BQ, however, are that its fine-tuning ability is limited by the total number of possible substitutions, and BQs are also more elec- trochemically unstable and susceptible to side reactions and degradation. Other redox active molecules, such as naphthoquinones, therefore, might be able to provide a better compromise and are worth investigating in future work.