Water desorption from rapidly-heated metal oxide surfaces-first principles, molecular dynamics, and the Temkin...

Quantitative understanding and control of water and impurity desorption from steel surfaces are crucial for high-voltage, pulsed power, vacuum technology, catalysis, and environmental applications. We apply a suite of modeling techniques, ranging from electronic density functional theory, to classical molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) methods to study the thermodynamics and kinetics of fast water desorption from different surfaces of hematite Fe₂O₃ and Cr₂O₃. Water binding energies on chromium oxide are found to be higher than iron oxide at zero temperature. MD simulations are conducted on Fe₂O₃ surfaces using thermodynamically consistent initial water inventory deduced with GCMC. The resulting time- and temperature-dependent desorption profiles on the Fe₂O₃ [Formula: see text] surfaces show multi-water cooperative behavior which cannot be deduced from zero temperature predictions, but which are in reasonable agreement with simple Temkin isotherm model estimates if finite temperature effects are incorporated into the Temkin binding energy parameter. Qualitatively different desorption behaviors associated with the [Formula: see text] and [Formula: see text] facets are discussed.