Interaction of Atomic and Molecular Hydrogen with Tholin Surfaces at Low Temperatures

Abstract

We study the interaction of atomic and molecular hydrogen with a surface of tholin, a man-made polymer considered to be an analogue of aerosol particles present in Titan's atmosphere, using thermal programmed desorption at low temperatures below 30 K. The results are fitted and analyzed using a fine-grained rate equation model that describes the diffusion, reaction and desorption processes. We obtain the energy barriers for diffusion and desorption of atomic and molecular hydrogen. These barriers are found to be in the range of 30 to 60 meV, indicating that atom/molecule-surface interactions in this temperature range are dominated by weak adsorption forces. The implications of these results for the understanding of the atmospheric chemistry of Titan are discussed.

30 pages, 11 figures

References in corpus (5)

• Molecular Hydrogen Formation on Astrophysically Relevant Surfaces
• Laboratory Synthesis of Molecular Hydrogen on Surfaces of Astrophysical Interest
• Molecular Hydrogen Formation on Ice Under Interstellar Conditions
• Molecular Hydrogen Formation on Amorphous Silicates Under Interstellar Conditions
• Molecular Hydrogen Formation on Low Temperature Surfaces in Temperature Programmed Desorption Experiments

Cited by in corpus (3)

• Laboratory Simulations of Haze Formation in the Atmospheres of super-Earths and mini-Neptunes: Particle Color and Size Distribution
• An Emerging Class of Bright, Fast-evolving Supernovae with Low-mass Ejecta
• H${}_2$ ortho-para spin conversion on inhomogeneous grain surfaces