Experimental and theoretical investigation of the degradation inhibition of Mg in the presence of carbonyl containing Mg battery boosters

Abstract

This study evaluates the corrosion inhibition performance of selected carbonyl-based compounds; oxalic acid, sorbitol, EDTA, sodium glycolate, and sodium salicylate on magnesium exposed to 0.5% NaCl solution using hydrogen evolution measurements over the temperature range 303–333 K. The inhibitors exhibited varying degrees of protection, with sorbitol and sodium salicylate demonstrating the highest inhibition efficiencies studied across the temperatures. Thermodynamic parameters such as entropy and enthalpy indicate endothermic and spontaneous adsorption behavior. Calculated Gibbs free energy values confirm the feasibility of inhibitor–surface interactions. Density functional theory (DFT) analysis provided insight into molecular reactivity, revealing that inhibitors with higher HOMO energies, lower HOMO–LUMO energy gaps, greater softness, and more favorable chemical potentials exhibited superior inhibition efficiency. The correlation between experimental data and quantum descriptors establishes electron-donating capability and molecular reactivity as key factors governing adsorption strength. Overall, the combined experimental and theoretical results highlight sorbitol and sodium salicylate as promising corrosion inhibitors for magnesium, contributing valuable understanding toward the development of Mg-based systems for energy and structural applications. However, sorbitol emerged with the highest inhibition efficiency (IE) and Utilization Efficiency (UE) suggesting that there may exist a relation between utilization efficiency and inhibition efficiency depending on molecular structure and electronic properties of the compound.