I accept the principle. But an ICE combusts with only oxygen from the atmosphere, too, theoretically. There’s theory and actual performance. It’s hard to believe that the other components of Earth’s atmosphere, or impurities in the iron are not going to be involved.
Also, for all of the BS surrounding carbon compounds in emissions, I can’t help but think that the real problem is the consumption of oxygen. This doesn’t help that, at all.
This is an Nickel Iron battery with the nickel electrode replaced with an air cathode with an O2 permeable membrane. The Iron side of the battery does the same chemical reactions as in the century plus old Edison cell. In a nickel Iron cell nickel oxide is reduced to metallic nickel and the OH ions flow to the Iron anode oxidizing Fe to FeO2 or FeO3 depending on the electrolytes voltaic potential. This type of air cell removes the nickel oxide cathode and uses O2 directly from the air to supply the needed OH ions to oxidize the Fe to Iron oxide. Reversing the reaction yields pure O2 at the air cathode there is no combustion at all it’s purely electrochemical reduction / oxidation reactions which unlike combustion are a second law of thermodynamics process not a first meaning the round trip efficiencies can equal the theoretical limits for faraday.
The atmosphere has sufficient O2 for centuries if every green plant died today before O2 levels would drop enough to make humans struggle to breathe. Most of the planet’s O2 is not produced in trees or forests it’s Marine green and blue green algae that produces the bulk of the O2 in the air humanity is in no danger of running out of O2.