Mechanistic Insights into the Inhibitory Role of Soil Humic Components in Iron (Oxyhydr)oxide Formation: From In Situ Kinetics to Molecular Thermodynamics

) of soil organic matter (SOM) binding to Fh and γ within the classical nucleation theory (CNT), linking heterogeneous nucleation barriers with organo-mineral bonding. This study is the first to provide in situ evidence of the inhibitory effects of soil humic components on the formation of Fe (oxyhydr)oxides and quantitatively establish that higher energy barriers to nucleation correlate with stronger organo-mineral bonding. This relationship suggests that good organic binders are good inhibitors for mineral formation, offering a novel perspective for predicting the formation and fate of soil minerals through the lens of organo-mineral binding free energies.