Authors: Andrew D. Doyle, Joseph H. Montoya, Aleksandra Vojvodic Year of publication: 2015 Journal: ChemCatChem DOI: 10.1002/cctc.201402864 Oxygen evolution and reduction offer a promising method of grid-level energy storage that could facilitate widespread adaptation of solar and wind power. However, the efficiency of these technologies is fundamentally limited by high overpotentials, which stem from correlations between adsorption energies of different reaction intermediates. We propose a scheme to circumvent these scaling relationships by defining a three-dimensional nanoscopic catalyst structure that capitalizes on different interactions between the intermediates and the catalyst owing to confinement. These nanoscopic channels reduce the theoretical overpotential for oxygen evolution on RuO2 by over 200 mV, corresponding to a 10 % increase in theoretical catalyst efficiency compared with a two-dimensional RuO2 surface. This approach may hold promise for other oxygen-evolution catalysts or, more broadly, to other reactions limited by (intermediate) adsorption-energy scaling relationships.