[bane]

The engine could draw on a smallish stored reservoir of H2 for normal operation. That reservoir could then be continuously supplied with H2 from the process until it hits some pressure metric after which the system temporarily turns off until the pressure in the reservoir dips below some threshold.

[knodi123]

okay, so if we need a fixed volume X, and we have a reservoir of (1/2) X, then we only have to wait on the slow trickle of the remaining 1/2 instead of the full amount.

Plus, what do you think the H2 is for? Generally, we think about using it in a fuel cell. Which generates electricity. And the idea of using electricity to split out H2 in order to generate electricity, all in one place....

You're adding complexity, but I'm not sure you're actually improving on simpler approaches.

[ars]

That doesn't make much sense. How are you going to make H2 inside a car? You need lots of electricity. Why not just have an electric motor?