Mesoscale hydrogen-bond network engineering controls quantum-coherent proton transport to suppress aluminum corrosion

The hydrogen evolution reaction fundamentally constrains the use of aluminum in acidic electrochemical systems. Existing strategies rely on alloying or interfacial passivation and overlook how the electrolyte controls proton transport (PT) to the metal surface. Here, we demonstrate that the Gutmann donor number (DN) provides a quantitative molecular lever to regulate PT through the aqueous medium and suppress hydrogen evolution corrosion of aluminum. High-DN additives reorganize the electrolyte into compartmentalized domains that disrupt long-range PT and force protons onto tortuous, high-barrier pathways. Using water (DN = 18 kilocalories per mole) as a benchmark, additives exceeding this threshold increase the hydrogen evolution overpotential by ~20 to 70 millivolts at 10 milliamperes per square centimeter and reduce the corrosion current density from 7.44 to 2.23 milliamperes per square centimeter, following an approximately inverse linear dependence on DN. These results establish a direct link between a molecular donor descriptor and mesoscale hydrogen-bond networks, revealing a materials-agnostic strategy for corrosion suppression through targeted control of proton dynamics.