Flexible Ligand in a Molecular Cu Electrocatalyst Unfurls Bidirectional O2/H2O Conversion in Water

The development of a bidirectional catalyst for oxygen reduction and water oxidation is the key to establishing sustainable energy transduction from renewable resources. We report a stable homogeneous molecular copper complex, comprising of a labile diimine-dioxime ligand framework, that enables rapid and complete 4e(-)/4H(+) electrocatalysis for both oxygen reduction (2.1(+/- 0.01) x 10(5) s(-1)) and water oxidation (3.2(+/- 0.01) x 10(5) s(-1)) in aqueous solution presumably via in situ formation of binuclear intermediates. Computational investigations unravel the pivotal role of the interactive flexible ligand scaffold in accommodating the copper-core in variable oxidation states and influencing the O-O bond cleavage/formation dynamics during the catalysis. This study sets up a template for designing molecular catalysts for mediating energy-relevant multielectron/multiproton reactions in both oxidizing and reducing environments.

Automated summary

The development of a stable molecular copper catalyst with a labile diimine-dioxime ligand framework enables rapid and complete electrocatalysis for both oxygen reduction and water oxidation. Computational investigations highlight the importance of the interactive ligand scaffold in accommodating variable oxidation states of copper and influencing the dynamics of O-O bond cleavage/formation during catalysis. This study establishes a template for designing molecular catalysts to mediate energy-relevant multi-electron/multi-proton reactions in both oxidizing and reducing environments.