Despite the Negative Waves regarding the low energy density of Hydrogen making it unsuitable for use as a transportation fuel, SwRI has in fact built a Hydrogen fueled, ICE powered tractor utilizing a modified Cummins engine designed for running on NG.

As with the Toyota car that gets around the problem of where to put all the tanks you need to hold the H underneath the car on the chassis,  the tractor has all the tanks strapped onto the cab like a backpack.  Looks like a standard Freightliner tractor was used for the prototype.



So, it appears that this actually CAN be done.  Beyond building enough renewable energy plants and getting the H refueling hardware into the main truckstops on the interstate, there's no major technical hurdle that needs to be overcome to make this work.  It just remains to be seen if they can produce enough Green Hydrogen, distribute the pumps and storage tanks and replace the current FF powered fleet at a cost that people can afford to pay for the products being shipped fast enough to keep this vital system from collapsing as the FFs become scarce and expensive.

https://interestingengineering.com/innovation/swris-heavy-duty-hydrogen-engine

SwRI's heavy-duty hydrogen engine offers 2,025 Nm torque with ultra-low emissions

RE