The formation and stability of carbonic acid on outer Solar System bodies

摘要

The radiation chemistry, thermal stability, and vapor pressure of solid-phase carbonic acid (H2CO3) have been studied with mid-infrared spectroscopy. A new procedure for measuring this molecule's radiation stability has been used to obtain intrinsic IR band strengths and half-lives for radiolytic destruction. We report, for the first time, measurements of carbonic acid's vapor pressure (0.290-2.33×10-11 bar for 240-255K) and its enthalpy of sublimation (71±9kJmol-1). We also report the first observation of a chemical reaction involving solid-phase carbonic acid. Possible applications of these findings are discussed, with an emphasis on the outer Solar System icy surfaces.