Modeling solid-liquid interface reactions with next generation extended Lagrangian quantum-based molecular dynamics

• DOI: 10.48550/arxiv.1907.06721
• Publication Date: 2019-01-01
• Authors: Kleiner, Kevin G.; Nair-Kanneganti, ...; Negre, Christian ...; Matanovic, Ivana; Niklasson, Anders...
• Keywords: Chemical Physics (physics.chem-ph); Condensed Matter - Materials Science; Physics - Chemical Physics; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; 7. Clean energy

Further research is needed to confirm the results<br/>We demonstrate the applicability of extended Lagrangian Born-Oppenheimer quantum-based molecular dynamics (XL-BOMD) to model electron transfer reactions occurring on solid-liquid interfaces. Specifically, we consider the reduction of O$_2$ as catalyzed at the interface of an N-doped graphene sheet and H$_2$O at fuel cell cathodes. This system is a good testbed for next-generation computational chemistry methods since the electrochemical functionalities strongly depend on atomic-scale quantum mechanics. As opposed to prior iterations of first principles molecular dynamics, XL-BOMD only requires a full self-consistent-charge relaxation during the initial time step. The electronic ground state and total energy are stabilized thereafter through nuclear and electronic equations of motion assisted by an inner-product kernel updated with low-rank approximations. A species charge analysis reveals that the kernel-based XL-BOMD simulation can capture an electron transfer between the PGM-free catalyst and a solvated O$_2$ molecule mediated by H$_2$O, which results in the molecular dissociation of O$_2$.<br/>