Exploring the Rehydroxylation Reaction of Pyrophyllite by Ab Initio Molecular Dynamics Molina Montes, María Ester Donadio, Davide Hernández Laguna, Alfonso Sainz Díaz, Claro Ignacio We have investigated the process of rehydroxylation of pyrophyllite as a limiting factor to the dehydroxylation upon thermal treatment. Car−Parrinello molecular dynamics simulations based on density functional theory have been used along with the metadynamics algorithm. Two possible rehydroxylation mechanisms reaction have been characterized, related to two possible intermediate structures along the rehydroxylation paths, and both involve the interaction of the apical oxygen atoms. At high temperature, the rehydroxylation reaction is highly competitive (free energy barrier (ΔF) = 1.5 kcal/mol) and inhibits the progress of the dehydroxylation reaction (ΔF = 40 kcal/mol). In addition to the rehydroxylation of the dehydroxylated structure, the water molecule supports the interconversion of the cross and on-site intermediates as well. Thus, rehydroxylation and interconversion among intermediates can justify the wide range of transformations as a function of the temperature observed experimentally. 2024-02-12T08:25:19Z 2024-02-12T08:25:19Z 2010-05-17 info:eu-repo/semantics/article https://hdl.handle.net/10481/88988 10.1021/jp102239k eng http://creativecommons.org/licenses/by-nc-nd/3.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License American Chemical Society