This study investigates how solute atoms influence the aqueous corrosion of high-strength Al-Zn-Mg-Cu alloys. The research reveals that the formation of nanocrystalline Al oxide films is critical for corrosion resistance, with solute partitioning between the oxide and the matrix, and segregation to the internal interface. The sharp decrease in Mg partitioning in peak-aged alloys highlights the impact of heat treatment on oxide stability and corrosion kinetics. Using deuterium (D) isotopic labeling, the study provides direct evidence that the oxide acts as a trap for hydrogen, potentially preventing H embrittlement. The findings suggest that Mg-enriched oxides are less protective than pure Al oxides, and that reducing Mg content in the surface oxide can enhance corrosion resistance. The study also shows that Zn and Cu become enriched in the matrix beneath the oxide, which can slow corrosion by acting as a barrier. However, the enriched layer can create a galvanic cell with the matrix, leading to accelerated corrosion at the interface. The research combines scanning flow cell, atom probe tomography, and multicomponent Pourbaix diagrams to elucidate the mechanisms of corrosion and solute behavior. The results provide insights into how to design more corrosion-resistant Al alloys for sustainable applications.This study investigates how solute atoms influence the aqueous corrosion of high-strength Al-Zn-Mg-Cu alloys. The research reveals that the formation of nanocrystalline Al oxide films is critical for corrosion resistance, with solute partitioning between the oxide and the matrix, and segregation to the internal interface. The sharp decrease in Mg partitioning in peak-aged alloys highlights the impact of heat treatment on oxide stability and corrosion kinetics. Using deuterium (D) isotopic labeling, the study provides direct evidence that the oxide acts as a trap for hydrogen, potentially preventing H embrittlement. The findings suggest that Mg-enriched oxides are less protective than pure Al oxides, and that reducing Mg content in the surface oxide can enhance corrosion resistance. The study also shows that Zn and Cu become enriched in the matrix beneath the oxide, which can slow corrosion by acting as a barrier. However, the enriched layer can create a galvanic cell with the matrix, leading to accelerated corrosion at the interface. The research combines scanning flow cell, atom probe tomography, and multicomponent Pourbaix diagrams to elucidate the mechanisms of corrosion and solute behavior. The results provide insights into how to design more corrosion-resistant Al alloys for sustainable applications.