maybe cheaper hydrogen
 

Justin Banner, MOTOR TREND, May, 2023, page-10, reported on 'New Water-Splitting Method Makes Hydrogen Like Plants Do', from the University of Michigan, computer and electrical engineering.
Self-healing, indium gallium nitrate on a silicon surface semiconductor catalyst technology, and a light source equal to 160-suns is part of the process.

As long as the electrolysis can be achieved using fewer energy than what could be actually useful to the engine, it might be okay. But I'd still take it with a grain of salt.