The conclusion states that the CO2 must first be dissolved in water, and that the approach probably isn't economical:
Yes, because that is where the H
+ is generated via electrical current, if I followed the process correctly.
I remember an experiment in High School where two electrodes were use to make H
2 and O
2 filling two glass upside down test tubes as the water was displaced by the gas, with the volume in the H
2 being twice the volume in the O
2 test tube ... because it came from H
2O ...
2H2O + energy → 2H2 + O2
But you knew that.
Enjoy