I don't recall the exact reasons why, I vaguely recall something like fuel degradation and / or expense of fuel material. (reddit.com)
Accelerated Discovery of Solar Fuels Materials by Integrating High Throughput Characterization and Machine Learning Techniques. (solarfuelshub.org)
«There's a widespread consensus that this is the right thing to do — to lay down a marker for the environment, and ban these hazardous fossil fuel materials forever in the City and County of San Francisco,» Arce said. (globalpossibilities.org)