H-2 adsorption on multiwalled carbon nanotubes at low temperatures and low pressures

We present an experimental study on H-2 adsorption on multiwalled carbon nanotubes (MWCNTs) at low temperatures (12-30 K) and low pressures (2 x 10(-5) Torr) using the temperature programmed desorption technique. Our results show that the molecular hydrogen uptake increases nearly exponentially from 6 x 10(-9) wt:% at 24.5 K to 2 x 10(-7) wt:% at 12.5 K and that the desorption kinetics is of the first order. Comparative measurements indicate that MWCNTs have an adsorption capacity about two orders higher than that of activated carbon ( charcoal) making them a possible candidate as hydrogen cryosorber for eventual applications in accelerators and synchrotrons.