Recent research from Northwestern University has uncovered the complex chemistry behind how soils, rich in iron oxide minerals like ferrihydrite, trap carbon for centuries. The study reveals that ferrihydrite's surface is a nanoscale mosaic of positive and negative patches, enabling it to attract a wide variety of organic molecules through multiple mechanisms beyond simple electrostatic attraction. These include chemical bonds and hydrogen bonds, which stabilize organic compounds and prevent their decomposition. The findings explain why soils can act as one of Earth's largest and most durable carbon sinks, storing roughly 2,500 billion tons of carbon globally. The research involved high-resolution molecular modeling and atomic force microscopy to map ferrihydrite's surface charges and interactions with organic molecules such as amino acids, sugars, and ribonucleotides. The diverse binding strategies—ranging from electrostatic interactions to covalent bonds—help protect organic matter from microbial degradation, thus contributing to long-term carbon storage. Understanding these mechanisms enhances knowledge of the global carbon cycle and the role of minerals in climate change mitigation.