[Okieshooter]

Let’s see CO2 has one carbon atom and two oxygen atoms. Methane is CH4, that is one carbon atom and 4 hydrogen atoms. I never see in the article where the hydrogen atoms are going to come from. Besides as cheap as methane is today I don’t see the point.

[Svartalfiar]

To test the nanoparticles’ reactivity, Xu placed the electrode in a beaker of solution and bubbled carbon dioxide into it. He applied a small voltage to the electrode, and measured the resulting current in the solution.

I would assume the solution contains mostly water. Which would, of course, contain the necessary H for the process.

[Elderberry]

The reaction took place in water. So I assume the water was the source of the hydrogen.

[Squawk 8888]

The process involves immesing the electrode in water through which CO2 is passed, so the current will break down the water molecules to obtain the hydrogen. The reaction produces 3 molecules of oxygen for each molecule of methane: 2H2O + CO2 = CH4 + 3O2

[Squawk 8888]

My bad- the reaction is produces 2 oxygen molecules for each methane molecule:

4xH2O + 2xCO2 = 2xCH4 + 4xO2

There is no “free” energy, however if the technology is more efficient than existing processes to create synthetic hydrocarbons it could be useful.