Replacement reactions for carbon geosequestration may be faster in calcium olivine vs magnesium olivine

CO 2 mineralization is the safest CO 2 geosequestration method with the highest sequestration capacity. Even though there have been lab and pilot-scale demonstrations, the complex chemical reaction is still elusive at atomic level. Here, I show that the ab initio molecular dynamics (AIMD) and metadynamics simulations enable quantitative analysis of reaction pathways, thermodynamics, and kinetics of the Mg 2+ and Ca 2+ ion dissolutions from olivine minerals, which have high weathering potential for carbonation process. The leaching of Ca 2+ from the Ca-olivine surface is a ligand exchange process that results in a much lower energy barrier with 10 3 times faster dissolution rate compared to the leaching of Mg 2+ , which the tight magnesium sites on the forsterite (Mg-olivine) surface forbid ligand exchange. These results provide indication on water capabilities in solvating Ca 2+ and Mg 2+ that are relevant to mineral carbonation and can help the evaluation of potential enhanced CO 2 mineralization mechanisms.