I didn’t know about hydrogen and its need to be super-chilled, which probably explains the brittleness of metal comment. I know in high school, I put an electric current on a copper plate and the bubbles where hydrogen that we captured and lit. The result was a “pop” and a small amount of pure water. I thought the idea was to put windmills out in the ocean, use the electricity to perform electrolysis, and pump the hydrogen to shore in pipelines for processing and distribution. Still, it does seem to be yet another waste of taxpayer money.
Hydrogen is a very tricky element to deal with. It’s so small that it passes through just about anything. Hydrogen Embrittlement is caused when hydrogen is trapped in between the molecules in a metal. The hydrogen forms microscopic gas pockets that substantially weaken the metal part. Another problem with hydrogen is that it has a very wide upper and lower explosive limit. If I remember correctly, it’s something like 5-95 % fuel to air ratio. For example, gasoline is somewhere around 14-21 % fuel to air ratio.
Hydrogen embrittlement is not a low temperature thing. The H2 diffuses into the metal and screws up the vanderwals attraction.