| Summary: | Abstract CO2 mineralization is the safest CO2 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 Mg2+ and Ca2+ ion dissolutions from olivine minerals, which have high weathering potential for carbonation process. The leaching of Ca2+ from the Ca-olivine surface is a ligand exchange process that results in a much lower energy barrier with 103 times faster dissolution rate compared to the leaching of Mg2+, which the tight magnesium sites on the forsterite (Mg-olivine) surface forbid ligand exchange. These results provide indication on water capabilities in solvating Ca2+ and Mg2+ that are relevant to mineral carbonation and can help the evaluation of potential enhanced CO2 mineralization mechanisms.
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