Dynamic Simulations of Electron-Ion Interactions in Hot Electron-Driven Surface Catalytic Reactions

Understanding how optical lasers initiate surface chemical reactions of adsorbates on metal surfaces is essential for identifying reaction pathways and accurately modeling catalytic processes, with the goal of designing catalysts with high efficiency and selectivity. Recent advances in optical pump and femtosecond X-ray spectroscopy enable the observation and differentiation of the time scales associated with electron excitation, adsorbate mode excitation, and phonon thermalization and ultimately chemical reaction. Upon laser excitation, electrons are excited and rapidly thermalize to several thousand Kelvin within ~100 fs. Energy is then transferred from hot electrons to phonons via electron-phonon coupling, resulting in phonon heating within ~1 ps. Both hot electrons and phonons can drive surface reactions, and the precise mechanisms of charge and energy transfer on the ps time scale often remain elusive. We report initial attempts to treat both hot electrons and hot phonons simultaneously in driving a surface chemical reaction.