I’ve built fuel cell powered bikes – the fuel storage is the problem, Air Products get jittery when you tell them you’re strapping a high pressure hydrogen tank to a bicycle 🙂
The matrix storage canisters are much better, but expensive. There are some fuel cells that burn methanol – much better as it’s a liquid so you can tank it, though it’s a bit toxic. They really do the opposite of this process, they crack the methanol to get CO2 and hydrogen, then burn the hydrogen in a fuel cell.
The advantage of this process is that it produces a fuel that’ll burn in unmodified petrol engines – I’m not sure why they’re not electolysing water, though, that seems simpler.