“I just KNEW I shudda been paying attention in chemistry class when the H and the O2 were combined and magically got some CARBON to cling to the water produced.”
Even 3rd graders know it not HO2.
I also took chemistry classes when young. But the point is that the hydrogen and oxygen stored in fuel cell vehicles has to come from somewhere. Plants that generate hydrogen use various methods, and they release various chemicals as a by-product. A great deal of CO2 is released in the manufacture of hydrogen - this offsets the goals of greenies that say fuel cells are non-polluting, because they are worse than gasoline in releasing CO2 and other no-no's into the atmosphere.
Other chemicals can be consumed and altered during the process, including aluminum, which consumes a lot of energy to create from ores. Fuel cells are exotic devices that are better relegated to space-craft and other tightly controlled environments. There is no free lunch with fuel cells.