Desorption Lifetimes and Activation Energies Influencing Gas-Surface Interactions and Multiphase Chemical Kinetics

Abstract. Interfacial and multiphase chemical processes involving gases typically involve adsorption and desorption onto liquid or solid substrates. The desorption energy, which depends on the intermolecular forces between adsorbate and substrate, determines the residence time of chemical species at the interface. In this study, we demonstrate how variations in desorption energy and temperature influence the net uptake or release of gas species, which in turn affects the rates of surface and bulk reactions, surface-bulk exchange, and the equilibration time scales of gas-particle partitioning. We survey experimentally and theoretically derived desorption energies to develop a parameterization that enables the prediction of desorption energies based on the molecular weight, polarizability, and oxygen to carbon ratio of the desorbing chemical species independent of substrate-specific properties, which is possible because of the dominating role of the desorbing species’ polarizability. The data and analyses compiled in this study provide new insights into the relationship between desorption energy and enthalpies of vaporization and solvation, reflecting the central role of desorption in the multiple steps of interfacial exchange and multiphase processes, including mass accommodation and heterogeneous chemical reactions. Practical implications are discussed for gas-particle partitioning, organic phase changes, secondary organic aerosol formation, and indoor surface chemistry. We conclude that future research in aerosol, atmospheric, and environmental physical chemistry, air quality, climate, and Earth system science as well as chemical engineering and materials science may benefit from further insight and constraints on the influence of desorption lifetimes and energies on multiphase processes and their temperature dependence.