[stephengillie]

The device generates a lot of O2 as a "waste product" (obviously) so could this be a viable way to oxygenate an atmosphere?

It's somewhat amazing that they can use such common metals for both catalysts. Also it's remarkable that only 1.5V is required for the operation. That's a common output voltage for solar panels. This design should be ripe for space travel applications. (I think the current solution produces electricity by recombining hydrogen and oxygen, so maybe this could also be an input for that?)

[userbinator]

The oxygen is not really a "waste product" - it just balances out the O2 that gets turned back into water when the hydrogen is burned...

[stephengillie]

Calling it a waste product here was mostly in jest. It's not every day that oxygen is the byproduct of a process, and not the goal itself.

This is something I'd forgotten about this process - use energy to separate hydrogen and water, then recombine later to release the energy. And the waste product from this is the water used to start the process (and the energy and heat lost to entropy). Very clean!

[masklinn]

> The device generates a lot of O2 as a "waste product" (obviously) so could this be a viable way to oxygenate an atmosphere?

Oxygenating atmospheres is easy (and obviously dangerous if you get high partial pressures), the issue is generally scrubbing CO2 out.

[stephengillie]

If you add enough oxygen, and keep adding oxygen, then eventually you'd get enough to breathe?

Earth air is mostly a mixture of 72% nitrogen, 24% oxygen, 6% carbon dioxide, and other stuff. Could humans breathe if they were in an environment that was 78% carbon dioxide and 24% oxygen? (IANADoctor)

[masklinn]

> If you add enough oxygen, and keep adding oxygen, then eventually you'd get enough to breathe?

If you add enough oxygen and keep adding oxygen, eventually everything is on fire.

> If you add enough oxygen, and keep adding oxygen, then eventually you'd get enough to breathe?

Nope. As the sibling comment noted, around 1% CO2 will start making people uncomfortable and stuffy (the human body is not sensitive to lack of oxygen so much as excess of CO2, that's why e.g. nitrogen suicide is almost painless), and concentrations above 7% CO2 start being lethal regardless of oxygen presence.

But CO2 has significant effects long before that, studies have shown decreased cognitive abilities starting at ~0.1% CO2.

[Vendan]

Survive? No way. C02 concentration is between 0.036% and 0.041%. 1% would be uncomfortable and cause you to be drowsy. 7%~10% would lead to suffocation.

[samstave]

Assuming a planet has water, would it not be safe to assume it also already has an atmosphere?

Unless - you have a nuclear powered device which melts trapped CO2 ice and then generates O2?

[JshWright]

Not really, no.

We're finding water (even liquid water) is actually _really_ common in our solar system (and presumably, in the universe as a whole).

Breathable atmospheres, on the other hand, are pretty rare.