Toyota has also pitched actually burning the hydrogen, but that’s even stupider. For starters you still get NOx formation by burning it, plus your efficiency is

Toyota has also pitched actually burning the hydrogen, but that’s even stupider. For starters you still get NOx formation by burning it, plus your efficiency is even lower. The problem with synthetic fuels isn’t the technology, it’s the economics. Synthetic fuels, to be remeotely green, need hydrogen created from electrolyzing water. That need to be done with 100% green energy (and new green energy, not simply pull from the grid to cause fossil fuel plants in o come online). Then you need carbon from someone here other than fossil fuels. Direct air capture is what many look at, and that’s very expensive because of the chemistry and thermodynamics. (You’re trying to pull co2 out of the air, something in concentrations in the parts per million). At the end of this Rube Goldberg operation you’re left with a fuel that’s going to cost 10x the price. And the only way the price goes down is if people buy a lot of it so that the technology can improve and so the plants increase to get economies of scale. Porsche is building a plant for this. But idk about you, but I doubt there are enough people who care enough about their car, and could afford, to pay >40$/gallon for gasoline.