Take this with a BIG grain of salt, but I think I read that Fullerenes were sponges for hydrogen...

Hydrogen easily dissolved in solids- remember the cold fusion fiasco? Remember that they were using Palladium? Palladium soaks up Hydrogen like a sponge.

When I was a student I built a damn good vacuum chamber (If I do say so myself) It achieved pressures ~10^-13 to 10^-14 of an atmosphere- one of my limiting realities was that hydrogen dissolved in the steel was constantly outgassing. My understanding of the process was that hydrogen was dissolved in the steel during the making of the steel...

The atomic hydrogen stays in the steel, but when 2 atoms meet and form H2 on a surface they can then leave the surface- and contaminate a vacuum chamber. I THINK that you can reduce this problem by annealing the steel in an inert gas atmosphere- like argon....

WOW that was a lot of irrelevent info you did not ask for- Oh well....