There is an argument for an additional catalytic mechanism which exacerbates ferricyanide losses in the presence of some anthraquinones. Recalling that ferricyanide is known to degrade in alkaline conditions via the reversible loss of cyanide ligands, any process that removes these cyanide ligands could therefore be expected to increase the rate of ferricyanide degradation. In our on-line simulated-crossover experiments, formamide was found to form after the addition of 2,6-DHAQ to ferricyanide. Formamide is a known intermediate product of cyanide decomposition in aqueous environments. The on-line simulated-crossover results indicate that 2,6-DHAQ increases the rate of formamide formation in ferricyanide, which suggests it could be catalysing the dissociation and decomposition of the cyanide ligands. Interestingly, when 2,6-DHAQ is added, there is also evidence that the rate-determining step in ferricyanide removal is changing. In the absence of 2,6-DHAQ, ferricyanide losses occur at the same rate in D2O and in H2O. However, in the presence of 2,6-DHAQ, an inverse kinetic isotope effect was observed, suggesting that the rate determining step for ferricyanide removal involves the breaking or formation of an R-H bond. Anthraquinones are excellent catalysts for the formation of hydrogen peroxide (H2O2) from oxygen and hydrogen. Roberts Jr. et al. also reported that anthraquinones can catalyze H2O2 formation in the absence of oxygen, via the nucleophilic addition of hydroxide ions. In industry, H2O2 is used to treat wastewater contaminated with free cyanide, and it can therefore contribute to the removal of ferricyanide. Furthermore, H2O2 is also known to reduce ferricyanide to ferrocyanide in alkaline environments, resulting in the evolution of oxygen. In the recent report by E. Fell et al., oxygen was detected in cycled ferrocyanide electrolyte. The authors attributed this oxygen to a coupled chemical OER, that drives the reduction of ferricyanide. Perhaps some of the contributions to the oxygen they observed could be attributed to a chemical OER driven by reactions between ferricyanide and H2O2. Interestingly, iron oxide hydroxides have also been reported as catalysts for the OER in alkaline conditions. Therefore, the formation of these solids could result in further decomposition of the electrolyte. However, for both these theories, is still hard to explain why the hydroxyl functionalised anthraquinone molecules drive these side reactions the most.