Formation of molecular hydrogen on amorphous silicate surfaces [article]

Ling Li, Giulio Manico, Emanuele Congiu, Joe Roser, Sol Swords, Hagai B. Perets, Adina Lederhendler, Ofer Biham, John Robert Brucato, Valerio Pirronello, Gianfranco Vidali
2007 arXiv   pre-print
Experimental results on the formation of molecular hydrogen on amorphous silicate surfaces are presented and analyzed using a rate equation model. The energy barriers for the relevant diffusion and desorption processes are obtained. They turn out to be significantly higher than those obtained for polycrystalline silicates, demonstrating the importance of grain morphology. Using these barriers we evaluate the efficiency of molecular hydrogen formation on amorphous silicate grains under
more » ... ar conditions. It is found that unlike polycrystalline silicates, amorphous silicate grains are efficient catalysts of H_2 formation in diffuse interstellar clouds.
arXiv:0709.2472v1 fatcat:zxwglcqpujc7lbzrh5oqbsuuli