I recently learned that monoatomic hydrogen passes directly through solid aluminum and even combines inside aluminum to form $H_2$ which cannot pass through solid aluminum and therefore causes deterioration, blackening, and flaking. Source
I am curious if mono-atomic hydrogen is capable of passing through any other solds?
I think "Hydrogen Embrittlement" is the topic you need to research - see the Wikipedia Page for this topic. From the Wikipedia page, we have the following list for materials that are especially likely to embrittle by this mechanism (surely not an exhaustive list):
High-strength and low-alloy steels, nickel and titanium alloys are most susceptible. Austempered iron is also susceptible.
and
....the elongation at failure of 17-4PH precipitation hardened stainless steel was measured to drop from 17% to only 1.7% when smooth specimens were exposed to high-pressure hydrogen
Amongst those which withstand or are least affected by this effect are:
... austenitic stainless steels, aluminum (including alloys), copper (including alloys, e.g. beryllium copper)...
The effect is not strictly confined to monoatomic hydrogen: splitting of diatomic hydrogen into two atoms at the surface of a container followed by diffusion into the container wall is a low-probability (probability increasing with pressure) but extremely important process over time, with obvious implications for the storage of high pressure hydrogen.
Embrittlement is clearly of importance in the design of containers - especially since the use of high pressure hydrogen made by "central" solar or other alternative energy plants is foreseen to be an good way to realise an energy source with oil's high transportability. The ability to lift a tonne one kilometer into the air with a cupful of oil is a vital property in mechanized agriculture, for example, where there are obvious problems in the use of nontransportable centrally generated electricity.
