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Abstract A direct electrosynthesis of H₂O₂from either O₂or H₂O is an attractive strategy to replace the energy‐intensive industrial anthraquinone process. Two‐electron water oxidation reaction (2e‐WOR) offers several advantages over the oxygen reduction reaction such as better mass transfer due to the absence of gas‐phase reactants. However, 2e‐WOR is a more challenging and less studied process with only a handful of metal oxides exhibiting reasonable activity/selectivity properties. Herein, we employ density‐functional‐theory calculations to screen a variety of metal‐nitrogen‐graphene structures for 2e‐WOR. As a consequence of scaling between the adsorption energies of reaction intermediates, we determine a linear relation between selectivities for the first and second reaction steps of 2e‐WOR, viz. that if selectivity toward adsorbed OH is improved, then selectivity toward H₂O₂at the subsequent step is decreased. We also find that selectivity and activity are linearly scaled in such a way that a higher activity (i. e., a lower overpotential) leads to a lower selectivity for the H₂O₂formation step. Based on the obtained results several chemistries, e. g., containing NiN_x−C moieties, are predicted to rival the best‐performing metal oxides such as ZnO and CaSnO₃in terms of combination of their activity/selectivity characteristics for 2e‐WOR. 

Abstract Based on the coincident onsets of oxygen evolution reaction (OER) and metal dissolution for many metal‐oxide catalysts it was suggested that OER triggers dissolution. It is believed that both processes share common intermediates, yet exact mechanistic details remain largely unknown. For example, there is still no clear understanding as to why rutile IrO₂exhibits such an exquisite stability among water‐splitting electrocatalysts. Here, we employ density functional theory calculations to analyze interactions between water and the (110) surface of rutile RuO₂and IrO₂as a response to oxygen evolution involving lattice oxygen species. We observe that these oxides display qualitatively different interfacial behavior that should have important implications for their electrochemical stability. Specifically, it is found that IrO₂(110) becomes further stabilized under OER conditions due to the tendency to form highly stable low oxidation state Ir(III) species. In contrast, Ru species at RuO₂(110) are prone to facile reoxidation by solution water. This should facilitate the formation of high Ru oxidation state intermediates (>IV) accelerating surface restructuring and metal dissolution.