The corrosive anions (e.g., Cl⁻) have been recognized as the origins to cause severe corrosion of anode during seawater electrolysis, while in experiments it is found that natural seawater (~0.41 M Cl⁻) is usually more corrosive than simulated seawater (~0.5 M Cl⁻). Here we elucidate that besides Cl⁻, Br⁻ in seawater is even more harmful to Ni-based anodes because of the inferior corrosion resistance and faster corrosion kinetics in bromide than in chloride. Experimental and simulated results reveal that Cl⁻ corrodes locally to form narrow-deep pits while Br⁻ etches extensively to generate shallow-wide pits, which can be attributed to the fast diffusion kinetics of Cl⁻ and the lower reaction energy of Br⁻ in the passivation layer. Additionally, for the Ni-based electrodes with catalysts (e.g., NiFe-LDH) loading on the surface, Br⁻ causes extensive spalling of the catalyst layer, resulting in rapid performance degradation. This work clearly points out that, in addition to anti-Cl⁻ corrosion, designing anti-Br⁻ corrosion anodes is even more crucial for future application of seawater electrolysis.

Elucidating the structure-property relationship is crucial for the design of advanced electrocatalysts towards the production of hydrogen peroxide (H₂O₂). In this work, we theoretically and experimentally discovered that atomically dispersed Lewis acid sites (octahedral M–O species, M = aluminum (Al), gallium (Ga)) regulate the electronic structure of adjacent carbon catalyst sites. Density functional theory calculation predicts that the octahedral M–O with strong Lewis acidity regulates the electronic distribution of the adjacent carbon site and thus optimizes the adsorption and desorption strength of reaction intermediate (*OOH). Experimentally, the optimal catalyst (oxygen-rich carbon with atomically dispersed Al, denoted as O-C(Al)) with the strongest Lewis acidity exhibited excellent onset potential (0.822 and 0.526 V versus reversible hydrogen electrode at 0.1 mA cm⁻² H₂O₂ current in alkaline and neutral media, respectively) and high H₂O₂ selectivity over a wide voltage range. This study provides a highly efficient and low-cost electrocatalyst for electrochemical H₂O₂ production.