A substrate-guided integrated electrode framework for 2e-water oxidation to hydrogen peroxide.

Anodic two-electron water oxidation (2e-WOR) offers a promising route for electrochemical hydrogen peroxide (H2O2) production by enabling direct synthesis from water. While recent efforts have largely focused on improving the intrinsic activity of catalyst materials, the influence of other electrode components is often underappreciated, especially as an increasing number of catalysts are prepared on non-inert substrates. Accordingly, this review adopts an integrated-electrode perspective and examines how substrate selection and electrode fabrication influence the active-material properties expressed in the apparent rate and selectivity of H2O2 production. We highlight that the coupling between substrate chemistry and fabrication procedures can reshape the interfacial micro-environment and transport properties, and can strongly modulate the apparent 2e-WOR kinetics and H2O2 selectivity. For example, non-inert substrates may contribute additional anodic reactions or interfacial states that influence the measured response. This makes it difficult to distinguish the contribution of the catalyst layer from that of the underlying support. Moreover, components such as binders and additives frequently used in electrode preparations can reshape local wetting and transport near the electrode surface, changing the interfacial reaction environment and leading to pronounced shifts in the observed H2O2 selectivity. By considering electrode-level effects together with catalyst descriptors, this framework helps distinguish intrinsic catalytic behaviour from contributions arising from substrate and fabrication choices. We conclude by summarizing practical considerations and recommended controls for electrode-level evaluation in anodic 2e-WOR.