The reaction described in the paper doesn't have spare oxygen on either side, presumably because oxygen has a habit of destroying catalysts and being explosive when mixed with hydrocarbons. Instead hydrogen is required.
Of course, neither this nor the reaction mentioned in the parent comment matches up with the diagram in the linked article which says "water + CO2 => propane + water", which well, doesn't make sense..
So you would need to have two separate electrolyzing processes, one that isolates H2 and one that runs this operation? How much energy would have to go into the first one?
I’m asking because a lot of the demand for hydrocarbon that I see mentioned is for processes that have more efficient, non-hydrocarbon equivalents.
