It's a fantasy used to greenwash oil & gas companies. It'd be nice if it were practical, but it's not for a variety of solid technical reasons such as leaking through metal.
> solid technical reasons such as leaking through metal.
Where the heck did you read that.
H2 is such a tiny molecule that leaks out of everything making it a nightmare to try and seal pipework, and it will permeate (and embrittle) metals, namely steel.
It's idiotic to try and use it as a fuel. The money being wasted on H2 research should just go into purchasing more renewable power sources.
https://news.ycombinator.com/item?id=37836237
Leakage is one of many issues, but it's also not just solved by a special liner.