The modifications induced in boron in the recombination into molecular hydrogen under heating in thermal-desorption experimental conditions were investigated. The diffusion of H on pure and boron-doped graphite was studied in the density functional theory framework. The diffusion like mechanism leading to molecular hydrogen formation was also determined. It was found using calculations that the recombination was a result of desorption on pure graphite and diffusion on B-doped surfaces, while activation energy for the rate limiting step was half reduced by the boron.

Adsorption, Diffusion, and Recombination of Hydrogen on Pure and Boron-Doped Graphite Surfaces. Ferro, Y., Marinelli, F., Jelea, A., Allouche, A.: Journal of Chemical Physics, 2004, 120[24], 11882-8