Porsche is spending big bucks on exactly that technology. The energy needed to make the fuel is the hard part. If, like ethanol we use more energy (diesel) than we get back from the gas, what is the point. The corn farmers love having a full time customer, but only the huge government subsidies keep it in going.
Much like just using Hydrogen for fuel, great idea, just how do we get the hydrogen to burn. Same issues.
https://techcrunch.com/2022/04/06/porsche-synthetic-fuels-investment-sports-cars/