The influence of corrugation, impurities, heterogeneity of tube diameters, shape of the inter-channels, and C vacancies in the H2 uptake by a bundle of C nanotubes was studied. It was found that the existence of tubes of different chiralities and the presence of vacancies in narrow interstitials could both prevent the H adsorption, making the system less useful as a reservoir in fuel cells than previously thought.

Conditions for H2 Adsorption in the Interstitials of a Bundle of Carbon Nanotubes. M.C.Gordillo: Physical Review B, 2007, 76[11], 115402 (5pp)